Comrade, in a British context there is undeniably a correlation between the end of the death penalty and the rise of the murder rate, whether this or other factors are more important than the subsequent rise from 1965 onwards are of course debatable, but you cannot sit there and state that it has no deterrent effect on anyone, because you have no evidence to suggest that it doesn't.
In any case, for me, the death penalty is not primarily about deterrence, it is about justice and is the only sanction in law that has a 0% recidivism rate. Convicted murderers deserve to die, you disagree, but executing them is undeniably logical compared to your policy of keeping them locked up in prison posing a danger to other inmates and staff, feeding them, sheltering them and having them in danger of being released again.
The only potential objection I have to the death penalty I have is the risk of executing an innocent person, but in my opinion, that is an argument for tightening up the judicial process, not the penalty for a particular crime.
As for your comment on the police, your attitude that the police are somehow deserving of the hatred directed against them because of their 'attitude' is frankly pathetic.