No, for a couple of reasons.
1. If you allow a government a power, you
must assume that they will abuse it for purposely malicious ends at some point in the future, and judge if they deserve said power by that metric. The Death Penalty is ripe for governmental corruption and abuse against the common people of a nation.
2. A judicial system must operate in such a way as to cause as little harm as possible to those innocents who will inevitably slip through the cracks. More than one person has been posthumously exonerated of their so-called-crimes after they were murdered by the state. You can compensate someone who has been wrongfully imprisoned, but not someone who has been wrongfully killed.
3. Rehabilitation, or in the worst cases, separation, is a superior manner to conduct a legal system when compared to the knee-jerk desire for pointless bloodthirsty revenge.
4. [United States Specific] In an attempt to justify the continued use of the death penalty, those bound for execution are allowed many numerous appeals and stays of execution, all of which involve going to court. As I covered earlier, this doesn't actually keep innocent people from being killed, but it does mean a lot of trials, which cost a
lot of money. As in, way more than it would take to feed and clothe someone until they dropped dead of their own accord.
5. You cannot revoke another person's Right to Live, under any circumstances. That's why it's a
right, and not a privilege. (War and Self Defense, being "hot-blooded" situations, do not fall under this as they are not specifically out to end another person's life, but for a variety of sociopolitical reasons and defending your own Right to Live, respectively.)
6.
Red: Practicing death penalty.
Orange: Legally retains death penalty, does not practice.
Green: Death penalty abolished for all but special circumstances.
Blue: Death penalty abolished in full.
Autocratic, totalitarian nations that abuse human rights make up the majority of nations that still practice the death penalty, with the only notable exceptions being the USA, Japan, and India. This is not a trend I want my nation to be a part of.
7. By killing the criminal, they do escape having to spend the rest of their days in prison. While, as before, the primary function of the judicial system should not be punishment, forcing the criminal to stay alive for the remainder of their natural life leaves the potential of recognizing their actions as wrong. As we have no conclusive evidence of an afterlife, any kind of punishment
or repentance must take place while the criminal is still alive.