his father, then by his brother. He is the topic of many neighborhood superstitions and tales. For example, Miss Stephanie Crawford believes he was outside her window once looking in on her. The children are scared of being too close to the Radley property but by the end of the story, they begin to recognize that Boo's intentions are kind. InChapter 3, Atticus explains to Scout that "You never really understand a person until you consider things from his point of view." Scout matures throughout the novel and begins to consider her father's words, especially in the case of Boo.

Near the end of the novel, the two stories merge when Bob Ewell attempts to kill Scout and Jem. Bob is angry because Atticus makes it clear that he is the one that injures his own daughter. Boo Radley intervenes and kills Bob Ewell in the process. The sheriff and Atticus agree that it would be wrong to drag Boo into the spotlight, so they decide to stick with the story that Bob fell on his own knife. Scout agrees and says, "it'd be sort of like shootin' a mockingbird."

Harper Lee wants to look at more than just one kind of prejudice in her novel To Kill a Mockingbird. That's why she created the characters of Tom Robinson and Boo Radley.

The most obvious example of prejudice is the racism that boils up around the Tom Robinson case. Robinson, as a black man in the South, faces the same racial hatred that black people have had to endure there for hundreds of years. Sometimes this racism results in physical tragedy, even death, as with Robinson. But always it subjects the people involved (both the haters and the hated) to a diminished capacity to live their lives in a fully meaningful way.

With Boo Radley, we also see prejudice, but it is of a different nature. This is the prejudice that people engage in with their neighbors and other folks who aren't necessarily all that different from them. Boo Radley, and the other Radleys, were culturally similar to Scout's family and the rest of the white people of Maycomb County. But since they kept to themselves and lived in what seemed a peculiar way, they were subjected to unfounded speculation and character aspersions that were unjustified. 

To Kill a Mockingbird doesn't ask readers to simply look at the cruel and unjust actions of others, which is all to easy to do; it also asks readers to consider their own potential unfair actions and judgments. Is there a Boo Radley in your neighborhood?

Comparisons:  They were both sentenced by authorities of the law (Boo by a judge to the boy's school, Tom to jail), both treated unfairly (Tom by almost everyone, Boo by his father and brother), both misunderstood and misjudged, both key factors in the events surrounding the ending of the novel and Bob Ewell's attack, both key factors in teaching Jem and Scout about decency, morals, justice and humanity, both kind-hearted (Tom did work for Mayella often, Boo helped the kids out and befriended them), both were defended by Atticus (Tom literally with the trial, Boo when Atticus tries to protect Boo's privacy from the kids).  Both of their innocent natures are symbolic of the mockingbird's song, and how it is a sin to shoot those birds.

Contrasts:  Tom ended up being killed by a brutal society whereas Boo was just shunned by it.  Tom actually received a sentence from a jury that was his punishment-along with society's racism, whereas Boo was a victim only of an overbearing and cruel father.  Tom lived a normal life and Boo was a recluse.

Those are just a few ideas to get you started.  Good luck!

On the surface, there are not many similarities between Boo Radley and Tom Robinson.  However, if you look closely, they are both symbolically compared to mockingbirds.  Atticus tells his children it is a sin to kill a mockingbird.  Mr. Underwood compares Tom Robinson’s death to the senseless killing of songbirds, and Scout compares Boo Radley to a mockingbird.  Each of these men is a victim of society in a different way.  Tom Robinson was targeted because of his race, and Boo Radley for his eccentricity. 

The story of Tom Robinson is more serious.  As an African-American, Tom Robinson was constantly victimized.  When Bob Ewell saw him with his daughter, he cried rape.  The story of a white woman and a black man could not be tolerated.  Robinson was convicted even though he was innocent, and Atticus proved during the trial that no crime was committed.  Tom Robinson had one useless arm and could not have caused Mayella Ewell's injuries. 

The worse part is that Tom Robinson committed suicide in prison.  Since he was crippled, he was shot attempting escape.  Even Mr. Underwood, the town's racist newspaperman, considered Robinson's death a travesty.

Mr. Underwood simply figured it was a sin to kill cripples, be they standing, sitting, or escaping. He likened Tom’s death to the senseless slaughter of songbirds by hunters and children ... (Ch. 25)

Tom Robinson never did anything bad to anybody.  All he did was try to help Mayella.  For his trouble, he was arrested, tried, convicted, and shot, all because of the color of his skin.

Boo Radley is the Finches' reclusive neighbor.  He never comes out of his house, and Dill and the other children decide that he is lonely and they need to make contact.  They try getting a glimpse of him or leaving him notes.  Atticus warns them to leave him alone.  He feels that Boo and his family deserves privacy.

The children make progress though.  They bring him out of his shell, and he actually starts leaving them gifts.  He puts presents in a tree hollow, mends Jem's pants and leaves them for him when he loses them, and puts a blanket on Scout's shoulders secretly during the fire.  His final gift is to rescue the children from Bob Ewell.  

Heck Tate told Atticus that he was not going to tell anyone what Boo Radley did, to save Boo from the notoriety and nosy neighbors.  When Atticus asked Scout, she agreed.

“Yes sir, I understand,” I reassured him. “Mr. Tate was right.”
Atticus disengaged himself and looked at me. “What do you mean?”
“Well, it’d be sort of like shootin‘ a mockingbird, wouldn’t it?” (Ch. 30)

Boo Radley was a mockingbird because he was a victim of society's cruelty.  The children saw something in him that no one else did, and became his only friends.  He repaid their friendship by saving their lives.

The biggest comparison between Boo Radley and Scout Finch has got to be that both of them are misunderstood and not accepted for who they are. For some reason, people believe the worst about each one of them. For example, Boo Radley is first depicted as an out-of-control youngster who must be locked away so he doesn't embarrass his father in chapter one. In much of the same way, Aunt Alexandra seems to think that Scout is out of control and needs to change so she won't embarrass the family name. 

"Aunt Alexandra was fanatical on the subject of my attire. I could not possibly hope to be a lady if I wore breeches. . . furthermore, I should be a ray of sunshine in my father's lonely life. . . but Aunty said that one had to behave like a sunbeam, that I was born good but had grown progressively worse every year" (81).

Another example is how Boo Radley reaches out to make friends with the kids by leaving gifts in the knothole of his tree; but Mr. Nathan Radley fills up the hole with cement and stops the practice. Likewise, Scout wants to invite a schoolmate, Walter Cunningham, to her house sometime and Aunt Alexandra says no "because he is trash" (225).

Boo Radley and Scout Finch are also prematurely judged on a specific incident that seems horrible at the time, but given an opportunity to explain, it would show a nobler reason for their behavior. For instance, Boo Radley stabbed his father in the leg with scissors and he is demonized for it around the community. If he had gotten an opportunity to explain himself, maybe he would have said it was in self-defense or in the name of something noble. The same thing happened to Scout at Christmas time when Francis called her father mean names. Scout punches him in the name of honor and her father, but Uncle Jack spanks and disciplines her without allowing her to defend her case first.

All of these instances show that Boo and Scout seem to have a lot in common. They are misjudged, mistreated at times, and misunderstood. They are probably the most genuine characters in the whole book, too, because they are never hypocritical. They might be misfits of sorts, but they are kindred spirits as well.

The two plots of To Kill a Mockingbird connect in that they center on characters who are judged poorly by people who do not even know them. Tom Robinson and Boo Radley are actually two very compassionate people. However, Tom is falsely accused of being a rapist and Boo is thought to be a dangerous psychopath by the children. They are neither of these things. Those who know them understand that they would never mean anyone any harm. In this way, Tom and Boo are symbolic of the mockingbirds that Atticus instructs his children not to harm.

Despite their actual gentle nature, society percieves Tom Robinson and Boo Radley in a very negative light. Many, particularly the kids, assume that because Boo is a recluse, he must have a dark and dangerous nature. Just as Tom's race condemns him as a dangerous criminal due to the entrenched racism in society, the prejudices of Jem, Scout, and Dill cloud their perceptions.

In the end, one of the mockingbirds is killed as a result of his compassion and the other is forced to kill because of his. Tom feels bad for Mayella Ewell. That is why he helps her out when he can. The payment for his kindness is to be accused of rape and killed for it. Boo looks out for the Finch children. He leaves little gifts for them and mends Jem's torn pants. When the kids are attacked by Bob Ewell, Boo kills him. In this way, the sweet mockingbird that he is is forced to commit a terrible act.

These two plots in the story line are connected because they are both part of Scout's childhood experience. The story is related as a narrative flashback; events are perceived through the eyes of a child but 'filtered' by the mind of an adult.

The two plots are also related in theme. Both deal with the topic of preconceived ideas towards ostracized people. In the adult world, the trial focuses on an innocent man who is convicted of rape simply because he is a Negro. (His word will not stand against that of a white woman.) Scout's, Jem's and Dill's fascination with Boo Radley portrays the natural curiosity of children but also a need to 'be scared' and then to overcome the source of that fear.

In the end, the children do a better job at this than the grownups. Whereas Tom Robinson is first convicted and then shot to death, Boo Radley, who was "on trial" in the children's own kind of 'kangaroo court,' becomes their hero and friend.

Both plots are similar in that they focus on upholding human dignity and fighting prejudice. Both Atticus and Bo are each brave in their fight for these principles. However, the plots show the different reactions to fighting for these principles.
Bo is an outcast of the town. He has made a choice not to appear in public. However, at the end of the novel, Bo makes a choice to fight for right in order to save the lives of the Finch children. This act of entering society brings Bo acceptance. Ironically, this is the opposite reaction Atticus gets when he decides to defend Tom Robinson. Atticus' fight for right doesn't make him more accepted by society. In fact is threatens to cut him off from society.

Atticus Finch brought it up first. He said it was a sin to kill a mockingbird. 

"'Remember it's a sin to kill a mockingbird.' That was the only time I ever heard Atticus say it was a sin to do something, and I asked Miss Maudie about it."

Miss Maudie gives the best definition of a mockingbird:

“Mockingbirds don’t do one thing but . . . sing their hearts out for us. That’s why it’s a sin to kill a mockingbird.” 

Tom Robinson is a mockingbird in that he doesn't do one thing wrong. All he does is provide pleasure to the folks he encounters. That is exactly how he got in trouble. Tom Robinson was helping Mayella with some chores. He was humming a melody as he chopped up the dresser drawers. He was giving of himself charitably. He was in no way harming anyone. 

Then when Bob Ewell came home and found Tom Robinson, he set out to ruin his life. Tom was innocently helping Mayella when Bob Ewell accused him of raping his daughter. The white community assumed Tom was guilty, thus killing Tom with their conviction before he even had a fair trial:

Tom’s goodness is recognized by very few of the characters in the book. His willingness to help Mayella with the many tasks she has to perform around the house is seen by the white community as inappropriate. They can not understand why a black man would feel pity or compassion towards a white woman. They themselves would not feel the urge to help an Ewell, the most despised of the white population and so, to them, the only reason for Tom to offer such help would be for a sinister purpose.

Boo Radley is considered a mockingbird because he had no evil intentions against anyone. Boo was misjudged. Jem and Scout judged him based on rumors. Boo is not evil. He helps Jem and Scout out many times. First, he left gifts in the knothole of the tree. He has a warm expression of his affection for Jem and Scout. He sewed Jem's pants when Jem got caught in the fence and had to come out of his pants. 

Boo Radley puts a blanket on Scout the night Miss Maudie's house burns down. Most importantly, Boo saves Jem's and Scout's lives. On the night Bob Ewell attacks Jem and Scout, Boo kills Bob Ewell in his effort to protect Jem and Scout from Ewell's evil attack. 

Tom Robinson and Boo Radley never had intentions to hurt anyone. They are caregivers. They provide beautiful music for those they try to help. They never did anything but sing their hearts out through their good deeds. They were protectors of others. Both Tom and Boo are misjudged based on evil rumors. It is a sin to to kill Tom Robinson but he dies.

Boo Radley cannot live a life of privacy due to the evil rumors that circulate about him. It is a sin to treat him with such disrespect. 

The relationship changes throughout the book. At first, the kids think that Boo is a terrible monster and prisoner in his own home. When Boo begins to leave gifts in the knot hole for them and when he puts a blanket around Scout during the fire at Miss Maudie's house, the realize that maybe he isn't all that bad. Boo ceases to be an object of fascination for them during Tom's trial. But seeing the injustice that Tom suffers makes the kids understand why Boo chooses to stay in his house.

The kids come to see Boo as a real person when he saves them from Bob Ewell. Scout treats him as she would any neighbor. She understands now that Boo had been watching her and Jem the whole time, and that he was a true neighbor--looking our for them when they needed him. Though she never sees Boo again after that night, she still thinks of him fondly, as we can tell by her older self's voice in this story.

In To Kill a Mockingbird, both Arthur “Boo” Radley and Tom Robinson are subject to misunderstanding and mistreatment by many people in Maycomb. Radley is the subject of many rumors, in part because he is a recluse and few people know him personally. Instances of mistreatment by adults are not mentioned. Instead, the children’s harassment is emphasized. A contrasting situation is presented for Tom Robinson, who was apparently considered a respectable citizen until Mayella Ewell accused him of rape. His mistreatment takes precedence over misunderstanding, as he is tried and convicted, and then later killed.

In the early chapters of the novel, Scout provides a few of the many rumors that Maycomb people circulate about Arthur Radley. The fantastic stories that people invent and repeat serve to dehumanize the man, making him more like a fairy-tale monster than a real person. There are rumors about his being a peeping-tom, which have been supported by Miss Stephanie.

People said he went out at night when the moon was down, and peeped in windows....

Miss Stephanie Crawford said she woke up in the middle of the night one time and saw him looking straight through the window at her.

After Mayella accuses Tom of rape, many people in Maycomb discard whatever good opinion they had of this hard-working man. The idea that black men always lust after white women was engrained in their thinking. They find it unbelievable that he simply wanted to help her—on that day and earlier occasions. During the trial, the prosecutor, Mr. Gilmer, is outraged when Tom says he “felt sorry” for Mayella, and then suggests that Tom is being disrespectful to him when he asks about facing up to what he did.

“No, suh, scared I’d hafta face up to what I didn’t do.”

“Are you being impudent to me, boy?”

After the trial is over, Jem continues to be outraged at the guilty verdict, especially because rape is a capital offense. Later Atticus tries to explain the jury’s thought processes.

“Tom Robinson’s a colored man, Jem. No jury in this part of the world’s going to say, ‘We think you’re guilty, but not very,’ on a charge like that. It was either a straight acquittal or nothing.”

This is the only time that Atticus openly admits that the verdict was wrong and based primarily on race.

In Chapter 3, Walter Cunningham Jr. tells Jem that he is familiar with the legendary Boo Radley. As they walk past Boo's home, Walter says,

"Almost died first year I come to school and et them pecans---folks say he pizened 'em and put 'em over on the school side of the fence" (Lee 16).

Walter's comment reveals the negative rumors that surround Boo Radley. Children throughout the community fear Boo Radley and believe that he is a malevolent being. Rumors like these unfairly stigmatize Boo Radley and negatively affect his outward perception.

Following Tom's death, Scout describes the perspective of the prejudiced community members. Scout repeats what the community says about Tom's death by saying,

"To Maycomb, Tom's death was typical. Typical of a nigger to cut and run. Typical of a nigger's mentality to have no plan, no thought for the future, just run blind first chance he saw.... Just shows you, that Robinson boy was legally married, they say he kept himself clean, went to church and all that, but it comes down to the line the veneer's mighty thin. Nigger always comes out in 'em." (Lee 147)

These racist comments reveal the extreme prejudice against African Americans throughout the community. The prejudiced community members neglect to realize Tom's reasons for attempting to escape from prison. They perceive Tom to be an ignorant individual incapable of rational thought simply because he is a black man.

Tom Robinson and Boo Radley are both victims of society, and at the end of the book Boo Radley defends the children from Bob Ewell.

The book ends where it begins, in some ways.  Boo Radley is a big focus of the early chapters.  Then in the middle everything is about the trial.  Although Tom Robinson is dead by the end of the book, he is the reason why Bob Ewell attacks Scout and Jem.  Ewell feels resentful that the trial showed Robinson in a more favorable light than him, and he feels that justice has not been done.

Tom Robinson and Boo Radley are both compared figuratively to birds.  Tom Robinson is accused by a white woman of rape.  Boo Radley is accused of all kinds of terrible things, like peeping in people’s windows.  People ostracize him because he is too shy to come out of his house. 

When Scout and Jem received new guns, Atticus told them it would be a sin to shoot mockingbirds.  This sentiment is expressed again by Mr. Underwood in an editorial about Tom Robinson’s death.  Robinson felt dejected when he was convicted, and decided to take his chances going over the prison fence.  He was shot.

Mr. Underwood didn’t talk about miscarriages of justice, he was writing so children could understand. Mr. Underwood simply figured it was a sin to kill cripples, be they standing, sitting, or escaping. He likened Tom’s death to the senseless slaughter of songbirds by hunters and children … (Ch. 25) 

Scout is puzzled that Underwood would consider it a miscarriage of justice when Robinson was convicted.  However, he was innocent and everyone knew it.  Bob Ewell felt humiliated because the jury deliberated so long.  He threatened Atticus and spit in his face.  He did not feel that Robinson’s death was enough. 

When Bob Ewell attacks the children and Boo saves them, Atticus and the sheriff Heck Tate decide to say Ewell fell on his knife.  Scout understands that they are trying to protect Boo Radley from everyone getting involved in his affairs. 

“Scout,” he said, “Mr. Ewell fell on his knife. Can you possibly understand?”

... “Yes sir, I understand,” I reassured him. “Mr. Tate was right.”

Atticus disengaged himself and looked at me. “What do you mean?”

“Well, it’d be sort of like shootin‘ a mockingbird, wouldn’t it?” (Ch. 30) 

Scout realizes that Boo Radley doesn’t like attention, and everyone in the neighborhood would be bugging him if they knew he was a hero.  It would be an invitation for people to re-engage in Boo’s life, when he would rather leave them out.  He is not a monster, but he is shy.

Both Boo Radley and Tom Robinson are good people.  They want nothing more than to help others.  They are different, and so people do not understand them.  Tom Robinson faces racism because of the color of his skin, and Boo Radley faces isolation due to his troubled past.

At the beginning of the novel, the children view Boo Radley as the "malevolent phantom" and expand upon the rumors and legends they hear about him.They fear Boo and believe that he is a grotesque monster who wreaks havoc throughout the neighborhood. The children even create a game called "One Man's Family" in which they act out their imaginative ideas of what takes place in the mysterious Radley home. Dill is infatuated with the idea of getting Boo out of the house and the children attempt to make contact with Boo several times by looking into his window and leaving him notes.

As the novel progresses, the children's relationship with Boo gradually develops.Scout learns from Maudie that Boo's real name is Arthur and Maudie tells Scout that he was a kind child with a tragic life story. After Jem loses his pants while escaping from the Radley yard, he returns that night to find them sewn and folded neatly across the fence. Jem begins to wonder if Boo was responsible for mending his pants but is unsure. Jem and Scout then begin receiving small gifts in the knothole of the Radley tree. They aren't entirely sure who is leaving them gifts, but Boo's brother, Nathan, ends their communication by filling the knothole with cement. At this point, Jem is mature enough to believe that Boo is not the "malevolent phantom" they had once imagined while Scout remains naive and fearful of Boo. In Chapter 8, Miss Maudie's house catches on fire, and the children are told to wait in the Radley yard. It is a cold night, and Boo covers Scout's shoulders with a blanket to warm her without anyone knowing. The next morning, Atticus asks Jem and Scout who gave Scout the blanket, and the children are both unable to answer him. Atticus laughs and tells them that Boo Radley must of have given it to Scout. Scout nearly vomits, and Jem begins to make fun of her by pretending to be Boo. This moment is significant because Scout realizes that if Boo were the malicious individual they thought he was, then Boo would have harmed her instead of graciously giving his blanket to warm her.

For the remainder of the novel, the children's view of Boo drastically changes as they mature. Both Scout and Jem stop attempting to see Boo and begin to sympathize with his situation. They realize that he is simply a shy person who chooses to remain secluded in his house. At the end of the novel, Boo saves Jem and Scout's lives by stopping Bob Ewell's vicious attack. After the incident, Scout finally gets a chance to meet Boo face-to-face and sits on the porch with him before walking Boo home. For the first time in her life, Scout views their neighborhood from Boo's perspective and truly understands him as a person. By the end of the novel, both Jem and Scout are thankful to have Boo as their neighbor, and cherish their unique friendship with him.

The idea of the “mockingbird” is used throughout the novel as a metaphor for people who either do no harm or who contribute positively to society. Their positive role is easy to overlook because we take for granted the kinds of things they do. While they may not seem original, in the sense that the mockingbird imitates other birds’ songs, neither do they cause any harm. During the course of the novel, Tom did not commit a crime, but Arthur Radley did, yet Tom was incarcerated and killed, while Arthur continued to live peacefully at home. The novel’s theme of racial injustice is carried forward in these two contrasting examples.

When Atticus Finch tells his children that it’s wrong to kill a mockingbird, the statement is foreshadowing of Tom Robinson’s death. This “sin” is a collective wrong that the people of Maycomb, through the prosecution and the jury trial, inflict on Tom, which ultimately results in his death. Tom had tried to be kind to Mayella, but the white people resented the notion that a black person felt sorry for any white person. In addition, many Maycomb people seemed to believe that black men were sexual predators and rushed to judgment about Tom’s actions.

Arthur “Boo” Radley apparently suffered from agoraphobia, as he did not leave his house. The Finch children and their friend Dill made up stories about him and tried to spy on him, but he responded kindly with overtures of friendship. When Scout and Jem were attacked, Arthur left his home to confront Bob Ewell, killing him in the process. Sheriff Tate declines to arrest Arthur, although he is sure that he was the killer. Tate anticipates that the prosecutor would not pursue a trial, and if it came to that, that Arthur would be exonerated so Tate does not insert Arthur into the legal system.

In Harper Lee’s To Kill a Mockingbird, a mockingbird is a metaphor for purity and innocence. Boo Radley, Tom Robinson, and Atticus Finch are all metaphorical mockingbirds in different ways.

Atticus tells his children that killing mockingbirds is sinful because they are harmless creatures that do nothing “but make music for [people] to enjoy.” Mockingbirds symbolize goodness and innocence in the novel, and their qualities parallel those of three of the story’s most important characters.

Despite the rumors circulating about him, Boo is a kind, caring, innocent being. He does not bother anyone, and he tries to be helpful when he can. For example, he does not hesitate to risk his own life to protect Scout when Bob Ewell tries to kill her. He does not want credit or recognition for his good deeds; he simply wants to be kind and live in peace.

Tom is another example of a metaphorical mockingbird. He is a good man who wants nothing more than to earn an honest living and take care of his wife and children. Contrary to Mayella Ewell’s accusations, Tom is a gentle, non-violent, pure soul. Unfortunately, the people of Maycomb are so blinded by hatred and racism, they wrongfully convict Tom of a crime he did not commit. Tom is fatally shot while trying to escape from the prison he should not have been in. The Maycomb townsfolk metaphorically kill a mockingbird when they convict Tom.

Atticus is another example of the personification of goodness and innocence. He is fair-minded, kind, and tries to help those in need (even at his own expense). He decides to defend Tom knowing that Tom does not stand a chance at a fair trial because of the color of his skin. Atticus knows he will receive backlash for his decision, but he does not let that deter him and he remains determined to do what is right in spite of the threats and abuse he and his family endure.

The prejudiced, racist, hateful views and behaviors of the citizens of Maycomb are illuminated and emphasized through their terrible treatment of the mockingbirds of the town: Boo, Tom, and Atticus.

Near the end of Harper Lee’s novel To Kill a Mockingbird, Boo Radley steps in during the chaotic aftermath of Tom Robinson’s trial. Scout and Jem are walking home from the Halloween pageant in the dark, and Mr. Ewell tries to attack them. Ewell is furious because Atticus humiliated him at Tom’s trial, and he intends to get back at him by hurting his children. During this chaotic encounter, Boo Radley shows up and stabs Ewell, saving the children. He carries Jem home and makes sure everyone is safe.

This heroic act shows that Boo is not the scary person that many Maycomb residents believe, but is actually a caring, protective person. In the end, Scout tells Atticus that Boo is "real nice." This conversation shows how she has learned not to judge people without really understanding their experiences. She also learned this lesson by witnessing the racial injustice at Tom Robinson's trial.

The children are fascinated with Boo Radley, but Atticus tells him to leave them alone.

The entire town of Maycomb seems obsessed with Boo Radley.  He is a recluse who has not left his house since he was a teenager.  He has kind of a checkered past, but he is basically harmless and Atticus knows it.  He tells his children to leave it alone when they ask about Boo.

He said Atticus never talked much about the Radleys: when Jem would question him Atticus’s only answer was for him to mind his own business and let the Radleys mind theirs, they had a right to; but when it happened Jem said Atticus shook his head and said, “Mm, mm, mm.” (Ch. 1)

When Dill comes to Maycomb, he is passionately curious about Boo Radley.  He decides that Boo Radley is just misunderstood, and wants to make him come out.  The children always enjoyed acting out stories in the yard, and Boo Radley becomes a favorite.  Atticus does not approve.  He feels that the Radleys have faced enough trouble, and forbids his children from re-enacting their story on the lawn.

The children do not forget about Boo Radley.  They do not tell Atticus about the gifts he leaves for them in the tree, but they do ask him if Nathan told them the truth about the tree being sick when he cemented the knot hole.  Atticus is again evasive, not wanting his children to be near the Radley place.

Dill gets the idea of leaving a note for Boo, and they try to get it to him. Dill holds a bell to warn them if Atticus comes by, and Jem does not succeed in leaving the note.  He shows it to Atticus, who asks why the children are so intent on getting him to come out.

Dill said, “We thought he might enjoy us…” and dried up when Atticus looked at him.

“Son,” he said to Jem, “I’m going to tell you something and tell you one time: stop tormenting that man. That goes for the other two of you.” (Ch. 5)

Atticus tells them that Boo and the Radleys deserve their privacy.  This does not stop them.  They want to get a peek at Boo.  They try doing it at night when they won’t be seen.  Unfortunately, Jem loses his pants.  He tells Atticus that he was playing strip poker, and sneaks out to get them later.  He finds that Boo sewed them up so he would not get in trouble.

The transition in their relationship with Boo Radley and Atticus’s part in it happens when Scout finds a blanket on her shoulders during the fire at Miss Maudie’s house.  Jem immediately spills everything to Atticus, worried that he will tell Nathan Radley about the blanket and get Boo in trouble.  Atticus understands.

It was obvious that he had not followed a word Jem said, for all Atticus said was, “You’re right.  We’d better keep this and the blanket to ourselves. Someday, maybe, Scout can thank him for covering her up.” (Ch. 8)

Atticus does tell Jem not to let the incident with the blanket inspire him to “further glory.”  He wants the children to leave Boo alone.  In the end, it is Boo who saves them, from Bob Ewell.  Scout is very polite to him.  Atticus responds by thanking Boo for his children.

Before fully considering the question, I think it's important to consider Miss Maudie's quote about mockingbirds: "Mockingbirds don't do one thing but make music for us to enjoy...but sing their hearts out for us." Thus, mockingbirds try to create beauty in a world that often doesn't appreciate them.

Tom Robinson encountered trouble because he tried to help Mayella Ewell. He saw Mayella's need, with so many younger siblings running around, and every time he passed by the Ewell yard, Mayella seemed to have some chore that she needed help with: "choppin' kindlin', totin’ water for her..." Tom swears that he never set foot on the Ewell property without a direct invitation from Mayella. When he stopped by on the fateful day that would forever change the course of his life, he did so out of an ongoing sense of kindness, because, as he puts it, she "looked like she didn’t have nobody to help her." Tom must have known that he was putting himself in harm's way to come to the aid of a white woman—alone and without witnesses—in this societal context. Yet his sense of honor would not allow him to refuse to help a woman in need. Tom's "music" was his compassion and kindness, and he extended this to Mayella, who was instrumental in ending his life. Tom tried to create beauty in Mayella's world by showing her the kindness that she seemingly received from no one else, yet ultimately this kindness was taken advantage of, and Tom was left to pay greatly for his "crime" of compassion.

Boo shows similar compassion toward the Finch children at the end of the story. His life is devoid of kindness; he spends it locked away in his house like a virtual prisoner. Yet when Scout and Jem need him, he breaks free to rescue them. He flies to their rescue in spite of the way society views him; he has been ostracized and has been the subject of town rumors for decades. Yet his "music" of kindness leads him to the Finch children, and he rescues them from certain death at the hands of Bob Ewell.

A mockingbird's purpose is to create beauty in its world; both Tom and Boo try to reach out to those around them in kindness and compassion to cultivate more beauty in the lives they have the ability to influence.

It's also a sin to kill a mockingbird. Thus, it was a sin for the prison guards to kill Tom, and it would be a sin to subject Boo Radley to the justice system for the same reasons.

I agree with the previous editor. The mockingbird 'sings'. Boo and Tom sing.

That singing is an expression of their innocence. So for Tom, he sings when he sits on the witness stand, takes the ridicule of Mr. Gilmer, and tells the truth when Atticus calls upon him to do so. It would have been easy for Tom to confess to something he didn't do and hope for a gentler sentence. Oftentimes a court acts compassionately on a criminal they believe has remorse for their crime.

Boo likewise sings. His song is not audible. His gestures intended to develop relationship with children communicate his innocence. He communicates his innocence by acting when he is needed. He saves the children from Bob Ewell and that is the biggest statement any man could make on behalf of kids.

The mockingbird symbolism is rampant in To Kill a Mockingbird. Tom and Boo are certainly two of the primary adult examples. I'm not sure I would use the "fly" terminology extensively, but Tom certainly yearns for the freedom to flee from his incarceration as you have mentioned. Both Boo and Tom have the characteristics of the novel's explanation of the bird: Mockingbirds serve no purpose but to make music and make others happy. They do not destroy crops nor prey on other creatures. They are small and innocent beings. Tom and Boo both fit this criteria. I suppose Boo "flies" when he leaves the safety of his self-imposed exile within his home to save Jem and Scout, just as he does on the other occasions when he ventures into the outside world to mend Jem's pants and cover Scout from the cold.

Like the mockingbirds Atticus tells Jem not to shoot, both Boo and Tom are gentle and harmless. They do not hurt or destroy. In their own ways, both men bring goodness and joy into the lives of others. Also like the mockingbird, both men are defenseless against forces that would destroy them.

Boo Radley has been victimized since his youth by his family and his community. Effectively imprisoned in his own home, Boo has been made the monster in Maycomb. Despite these injustices, however, Boo has remained a good man. He takes pleasure in watching the children at play, gives them gifts that fascinate and delight them, and grows very protective of them. He saves Jem's and Scout's lives, at the risk of his own. Boo's heroism is kept quiet so that he will not have to endure public scrutiny. Scout, wise beyond her years. realizes that exposing Boo would be like killing a mockingbird.

Tom is a husband and father who takes care of his family and feels genuine compassion for Mayella Ewell. Tom understands Mayella's loneliness and miserable life, and he treats her with kindness. In return, he is arrested for a crime he did not commit, tried, convicted, imprisoned, and then shot to death. Atticus had told his children it was a sin to kill a mockingbird; Tom's destruction is sinful in every way. 

It would be tempting to characterize Boo's relationship with the kids as one of a person seeking friends as equals.  After all, the gifts that Boo gave in the tree knot are consistent with what kids might give to each other -- a piece of gum, an old spelling bee medal, etc.

Yet, the primary role that Boo serves is as a behind-the-scenes protector and caretaker of the Finch children and of Dill.  From silently putting the blanket around Scout's shoulders in Chapter 8 to mending Jem's ripped pants, Boo takes care of the children without his presence being known.

It is only in the final confrontation with Bob Ewell that Boo is forced to step out of the shadows and help the children in a way that, at last, reveals his true nature to the kids and to some of the other residents of Maycomb.  Had that event not occurred, Boo likely would have preferred to stay a silent, but important, protector for the children.

After Tom Robinson was convicted and was killed trying to escape, it seemed like things were back to normal.  Scout was to perform in a play.  On the way home she was attacked by Bob Ewell.  He attacks Scout to get revenge on Atticus for the way he and his daughter were cross examined in court during the Tom Robinson trial.  After the attack it is Boo Radley that carries Jem home.  Scout finally gets to meet Boo and decides he is not scary at all.  Throughout the novel Boo is watching the children and in someways protecting them.  He fixes Jem's torn pants earlier in the novel. He leaves gifts in the tree for them, and in the end he saves Jem and Scout by killing Bob Ewell.  This is in someways a redemption for Tom Robinson.  The idea that what comes around goes around is really proved true here.  Ewell lies in court, and that is what helped convict Tom Robinson, so in the end he pays for his evil by giving up his life.

Harper Lee uses an array of emotional techniques to describe and advance the relationship between the children and Boo Radley. In the first chapter of the novel, the children's fear of their unseen neighbor dominates their feelings. With the arrival of Dill and his own interest in the Radley House, the children grow bolder and curiosity seems to outweigh their fears. At first, the children only want to get a look at Boo to see that he really exists; it is Dill who suggests that they find a way to "make him come out." But when the gifts begin appearing in the knothole of the Radley oak, Jem and Scout finally realize that they could only be coming from Boo. At this point, the desire to repay Boo for his kindness takes over, and the children determine to become friendly with Boo. Lee mixes terror with humor on the night of the children's raid on the Radley's back porch: The kids manage to avoid the lurking shadow and Nathan Radley's shotgun blast, but Jem loses his pants in the process, providing Dill with his excuse of them playing strip poker--something that is both agreeable yet confusing to Scout. The children eventually feel guilt for invading Boo's privacy and "tormenting that man," just as Atticus has warned them. After Scout finds that it is Boo who places the blanket upon her shoulders to warm her on the night of Miss Maudie's fire, Jem promises that he "ain't gonna do anything to him" anymore, and both of the kids give up all forms of their Boo Radley games. But Scout never stops fantasizing about Boo, one day hoping to sit down and have a normal conversation with him. At the end of the story, after Boo has saves Jem's and Scout's lives, Scout feels guilt that they have never been able to

... give in return. We never put back into the tree what we took out of it: we had given him nothing, and it made me sad.  (Chapter 31)