James Van Praagh's 1997 book Talking to Heaven has a section subtitled Capital Punishment in its chapter Suicide. Below are some quotes from it.
"...not only is suicide wrong, but so is capital punishment.
"...When a person is violently taken out of the physical body before the predetermined, natural time for the soul to leave, there are spiritual consequences. As in suicide, the magnetic tides of the soul must stay within the earthly atmosphere until its natural time to leave. When a spirit of an individual is forced out of the body by capital punishment, the personality of the criminal remains exactly the same as it was prior to execution. When it reaches the other side, it is usually scared and angry because more than likely it is not highly evolved and is ignorant of spiritual laws. In most cases, such a soul roams endlessly throughout the lower astral world with other like-minded souls. Because these tormented souls carry a mind-set of anger and hatred, they often seek revenge for their untimely deaths. They search the earth for weak-minded humans whom they can mentally influence to kill or hurt others.
"...It only takes an instant for someone to see the Light of God and be transformed. Such a rehabilitated individual may one day help to prevent someone else from destroying another life. The door to growth and enlightenment must always be kept open.
"By capital punishment, we continue the propagation of violence upon one another.
"...If one is in full awareness of his Godself, he would know that killing someone is not even an option."