There are victims and families of victims who do not support the death penalty. A documentary aired in the UK a few years ago that spoke with the family of a prison officer (Daniel Nagle) who was murdered, the perpetrator (Robert Pruett) had been sentenced to the death penalty and the Nagle family were against the sentence -- even though they believe him to be guilty of the murder.

If you're in the UK you can watch that here: http://www.bbc.co.uk/iplayer/episode/b03zndw4/life-and-death...

I'm not quite sure if I'm interpreting your comment correctly, apologies if I've misunderstood the point you're making.

They are the last ones who should have an opinion on the matter, as pain clouds their judgement towards revenge.

Besides, they'd be saying the same things for anybody, if they were convinced or led to believe that he/she was the culprit, even if he/she were innocent.

Only if they were against the death penalty should they be heard, because that would be a sign that they speak putting revenge and petty sentiments aside.

The justice system shouldn't be a mechanism for revenge but for the protection of society.

There's a reason we don't let victims of crimes determine the punishment for the criminals.

Not this particular family, but here's an opinion of a few other families:

http://kwgn.com/2014/01/08/families-of-murder-victims-rally-...

The family almost always vents their anger at whoever the police tell them "did it", even if the police are wrong. Often they persist in that belief after DNA evidence or video evidence proves conclusively that the police were wrong.