Upon reexamining public opinion regarding the death penalty, about 80 percent support the death penalty, while about 10 percent oppose it. However, under the condition that we introduce a system of life imprisonment without parole, which currently does not exist in Japan, public opinion shifts to 52 percent against abolishing the death penalty, and 38 percent in support of it. According to these results, there seems to be among many a favorable view of replacing the death penalty with life imprisonment. (Source: "2014 Public Opinion Survey on the Basic Legal System," Cabinet Office) (https://survey.gov-online.go.jp/h26/h26-houseido/2-2.html)
As we delve into the subject of public opinion on this issue, the following arguments are made by individuals who support continuing the death penalty. First, they argue that it is the legal conviction of citizens that anyone who kills another person should have to pay with their own life. Next, the existence of the death penalty acts as a deterrent toward felonious offenses, such as murder. Finally, the death penalty is the ultimate and most effective method of protecting society from dangerous criminals. On the other hand, those who oppose the death penalty and support abolishing it claim that as long as the state forbids murder by law, it is irrational for the state itself to carry out murders, and because of this, it is not possible to allow it. In addition, the argument that the death penalty acts as a deterrent to crime has never been proven; in fact, some criminals commit murder hoping to receive the death penalty. And finally, it is not possible to rule out the possibility of a miscarriage of justice, and if such error is discovered after the fact, the punishment is irreversible.
However, it can be said that the opinions on neither side offer enough grounds for argument to fully support its legitimacy. Among advocates of the social contract theory, there are an equal number of people who are for and against the death penalty, and there is not enough meaningful data with regard to the deterrent effect against crime. In addition, although the argument about the possibility of wrongful sentencing is convincing in favor of abolishing the death penalty, the possibility of someone wrongfully convicted spending their entire life in prison, only to have it discovered after their death that they were innocent, can be said to be equally cruel.