My reason for supporting the death penalty for the crimes of murder and rape are the following:
1) I support eye for an eye. Not everyone supports eye for an eye and this is fine, but I support eye for an eye as my reason to support the death penalty for murder.
2) I'm fiscally conservative. Murderers and rapists cost taxpayers too much money. Usually, the most popular alternatives to these crimes is life in jail (with a small portion of people advocating for rehab for the murderers and a larger advocating this for rapists) but this still calls for jail for a certain amount of time and that is an expense I don't feel conferrable forcing the rape and murder victims to pay.
America (like most of the small dick west) treats their murderers and their child rapists better than the homeless. If your homeless, you have no home. You often have no reliable food source. You can murder someone or rape someone, get life in jail, and then force the victims of the crime to spend their tax dollars on keeping you alive. This is crazy and not something I can support.
Now the death penalty is more expensive than life in jail because of trials
The solution to this isn't to abolish the death penalty, but to make the process cheaper and quicker. If your convicted guilty of murder or rape, you have 1 hour left to live and after that, the state executes you (not by lethal injection, it's too expensive). If a murderer murders:
Up to 1 person: Death by firing squad.
2 people: Death by electric chair.
3 people: Death by guillotine.
4+ people: Death by hanging.
Multiply these numbers by 2.5 and the same penalty is applied to rapists.
We will make more mistakes, but the amount of money saved is a legitimate trade off to saving lives as what precedence indicates.
If you ask the typical person,
Are you willing to spend $1/day to save the life of a starving foreigner?
Most people would answer no since sponsoring children is done by a minority of Americans.
Life in jail for 25 inmates (because only 1/25 inmates are innocent) costs about $100 million.
If society is unwilling to spend $1/day to save the life of a child in poverty, why is society willing to spend $100 million on saving the life of a falsely convicted murderer or rapist (if they are innocent)?
Our murderers and rapists are treated better than poor foreign children and that isn't something I support.