I am against the death penalty for several reasons.
One, as long as there is a chance that an innocent person can be put to death, the price is too high. As people are often let out of prison after many years and having been found innocent due to new evidence, it is likely and probable that the wrong person has been put to death a time or two. There is no way to remedy this mistake when it happens.
Two, it is actually more cost efficient to carry out a life sentence than put a prisoner to death. Seriously. Look it up.
Three, with Europe refusing to sell us the drugs necessary for lethal injection, we are basically performing medical experiments on living, non-consensual people. That's inhumane at best.
Four, We are one of only 40 countries left in the WORLD who still perform this barbaric practice. Out of 195 countries, only 40 still put prisoners to death. Hint: it's because it is barbaric, inhumane, and outdated.
Five, the death penalty makes some people famous. Instead of deterring crime (like it was originally said it would do), it makes a certain kind of person more inclined to commit vicious crime for the celebrity status of death row and being put to death.
There's more reason, but I'll stop there