1、criminals 应该be locked up in prison(jails)。

　　2、can ensure a safe and comfortable living environment for law-abiding citizens. Thieves ，robbers，rapists and murders are dangerous，pose potential threat to the society

　　3、放到监狱教育是一个很好的方式，让他们知道侵犯其他人的权利是要付出代价的，这样就会减少他们再次犯罪的可能性

　　4、不但是punish criminals but also deters the potential criminals. 有些有犯罪倾向的人由于害怕被处罚，可能会放弃commit crime.

　　5、应该放到监狱。Just as the old saying goes， mercy to the criminal may be cruelty to the people.