Taken right from the text.

Another way in which the death penalty prevents murder is the elimination of vicious murderers from our society. If the vicious killer is dead, he or she will not be able to kill again. Most supporters of the death penalty feel that offenders should be punished for their crimes. Supporters of the death penalty are in favour of making examples out of vicious murderers, and know that the threat of death will indeed be enough to lower the crime rate. According to Isaac Ehrlich's study, published on April 16, 1976,eight murders are deterred for each execution that is carried out in the U.S.A. He goes on to say, "If one execution of a guilty capital murderer deters the murder of one innocent life, the execution is justified." To most supporters of the death penalty, like Ehrlich, if even just one life is saved, for countless executions of the guilty, the executions are justified. The theory that society engages in murder when executing the guilty is considered invalid by most supporters, including Ehrlich. He feels that execution of convicted offenders expresses the great value society places on innocent human life.


Ah, I see what I posted was from 76, what you posted was from 86, that's almost 20 years ago it really has no relevance today.