Against

I am going to have to support Praveer's position that it is morally wrong and that you cannot undo death. In many of cases people have been found innocent only after they are dead, they could have lived a long and lasting life after being released with their family and friends. If you support capital punishment, your supporting this.

On another token, keeping prisoners helps the economy. With every prison comes the need for people to run it. These people are regular people like you and I that are in need of work. From the guards to the construction workers who built the prison to those who maintain it; prisons create and maintain jobs. Jobs which pump money back into the economy which only provides economic growth.

Apart from being morally wrong to kill people even if they have killed, it would be impractical to kill them as it would destroy jobs and possibly throw the economy into a turn(depending on the makeup of inmates with fitting crimes for caoital punishment).