There is no evidence to suggest that Homer was trapped, and none to the contrary either. There is evidence to suggest that Emily killed Homer with poison.
In the spirit of conjecture, I'd agree with those above who suggest that Emily did not "trap" Homer but instead simply killed him.
In concurrence with the assertion that Homer is not trapped, he was probably snared by Emily in a devious plot to keep him from doing to her what all the other suitors had done--abandoned her. Without her father, who had prestige in the community, Emily cannot bear another insult.
How curious his name is! Rather than being suggestive of any grand hero or classic figure, he is barren (Barron) of any truly worthy traits. Ironically, however, he does become somewhat legendary in the town.
I agree with the above posts -- Homer is not trapped except by the fateful consumption of the poison and that is the whole point of the story. The ONLY way that Miss Emily was going to be able to control him was through killing him. She clearly saw no other way to keep the man in her life and so she did what she had to do in order make sure he never left her.
It's hard to make the case that Homer is trapped since he leaves and then comes back. That clearly speaks of choice, though his decision to return is a fateful one, to be sure. It's equally hard to imagine Homer trapped in the house by Emily; instead, we have to assume he was duped or tricked into ingesting the poison. Trapped implies he was powerless, and he just doesn't seem so to me.
Homer Barron was not trapped. He had all the power in the relationship. When he came to town, all Miss Emily had left was her reputation and standing in the community. When Homer started escorting her around town, he took what was left of both of these. Even that, perhaps, Miss Emily could have accepted in the hopes of holding out for something better, but Homer proved to be unfaithful in word and deed. Was Miss Emily's murder (and we really have no doubt of that) of Homer Barron retribution, and then her subsequent relationship with the corpse remorse, or was it the other way around?
Homer Barron was trapped because he was living in the household of a co-dependent woman. Any man who lives with a woman who needs him (regardless of whether she actually loves, or wants, him) is a trapped man.
You can almost perceive that Homer was trapped because of his tendency to drink and hang out with other men. We know that he had homosexual tendencies, and that he was a drinker. If you add to this the fact that he had to come home to an older, co-dep and eccentric lady, you almost can understand why he needs to drink to get away from his reality.
And, of course...when he tried to get away, she killed him.
And slept with his corpse.