No. It is moral hypocrisy, saying you are going to kill someone because they have killed someone just doesn’t add up. With the lethal injection, thirteen states including Texas (which has killed over 500 with the death penalty out of around 1700) keeps their ingredients a secret to the American public. Even the Pope, if you’re religious, says that it is ‘inadmissible’
In my opinion the death penalty can be fair and unfair. It's fair to the families whose loved one's had been murdered at the hands of evil people. But it's unfair to some who have changed while rotting away in jail and die anyway. I think another way that it is unfair is that some people are accused when they hadn't even committed the crime leading to a death an innocent person who was just in the wrong place at the wrong time