I, too, have a hard time deciding whether victim impact statements, which are by definition emotional in nature, are more for the healing and sense of justice on the part of the victims, or if it should make a legal difference if the criminal for all intents and purposes did more "damage" with their particular crime, or created more victims.
For example, should a person who murdered someone with a family of ten be considered a more serious criminal because there are nine other grieving survivors, as opposed to "only" one or two? I think we can get into philosophical and legal trouble by going down that road.
That being said, someone who stole my car from my driveway vs. someone who carjacks me at gunpoint is not the same degree of criminality.
If I had to make a choice, I would say leave victim impact statements out of the sentencing process. There is just too much potential for subjective punishments and inequalities in the justice system.
Victim impact statements are allowed at the sentencing phase of a trial. If a defendant is found guilty, a judge may hear and consider these statements in deciding on a sentence. In these statements, the victim or victims testify as to the impact that the crime has had on their life.
I do see the point of these statements. The defense attorneys will often focus on hardships that the defendant has gone through in asking for a light sentence. The victim impact statement balances this by reminding the judge about the effects that the convicted person's crime has caused to other people.
Even so, I'm not 100 percent convinced that these statements should be considered. For example, should you be punished more severely if you kill a person whose family loved him than if you kill someone who had no family? Isn't it the same offense (murder) and shouldn't it therefore get the same penalty?
On some level, the victim impact statements should be included as part of the sentencing phase. If the entire purpose of the justice system is to gain as much of a view of the crime as possible, then the victim impact statements have to be included because it represents the truly wronged party. To some extent, it is also a nod to the victim to allow their voice to be validated. Including them at the sentencing phase, after guilt has already been determined, makes sense to me. While the justice system strives to make sure that emotions are not involved in the calculations of guilt, the fact is that the subjective cannot be entirely overcome in the process of assigning blame or establishing guilt. To this point, including the victim impact statements in sentencing reflects the emotional component of these deliberations and the process of establishing justice.