The third argument is also utilitarian, although of a lower quality: the state saves money by killing murderers instead of keeping them in prison for life at the expense of the community.
第三点理由同样出于实用主义考虑，但质量却没有那么高：对杀人犯执行死刑而不是由社会出钱把他们终生养在监狱里，可以为国家节省下大笔的开支。