And the question should be, "Are you for the death penalty?"

Some crimes demand it.

What about murderers who kill somebody that should be going to testify on trial? Society should care that even the mob does not apply the death penalty, and in several places (like in Italy) this problem is far more urgent.

Very controverstal topic. I say no, but then there's so much more to it; for instance how bad/wrong is what a person has done, and what a country or culture considers the punishment to be.

I don't agree with the death penalty in most cases,because I know there are some mistakes and then if an innocent person is executed you can never bring him back.However in some extreme cases I think it could be appropriate.Generally I am against it.