The first issue stands as deterrence. A major purpose of criminal punishment is to conclude future criminal conduct. The deterrence theory suggests that a rational person will avoid criminal behavior if the severity of the punishment outweighs the benefits of the illegal conduct. It is believed that fear of death "deters" people from committing a crime. Most criminals would think twice before committing murder if they knew their own lives were at stake. When attached to certain crimes, the penalty of death exerts a positive moral influence, placing a stigma on certain crimes like manslaughter, which results in attitudes of horror to such acts. .
Studies of the deterrent effect of the death penalty have been conducted for several years, with varying results. Most studies have failed to produce evidence that the death penalty deterred murders more effectively then the threat of imprisonment. The reason for this is that few people are executed and so the death penalty is not a satisfactory deterrent. If capital punishment were carried out more often it would prove to be the crime deterrent it was intended to be. During highly publicized death penalty cases, the murder rate is found to go down but it rises back up when the case concludes. (Bailey, 42) .
When comparisons are made between states with the death penalty and states without, the majority of death penalty states show murder rates higher than non-death penalty states. The average murder rate per 100,000 population in 1996 among death penalty states was 7.1, while the average murder rate among non-death penalty states was only 3.6. A look at neighboring death penalty and non-death penalty states show similar trends as death penalty states usually have a higher murder rate than their neighboring non-death penalty states. (Horwitz, 87) .
The second issue in the capital punishment debate is vengeance, or the need for society to express sufficient disapproval for violent murders.