No, but it would gradually lower it. However, the rate of violent felonies to misdemeanors would rise rapidly (cf. Chen Sheng and Wu Guang uprising).

Many crimes are committed by repeat offenders so it would eliminate a decent chunk of crime. Over 60% of violent criminals in the US get rearrested for another crime. Almost 40% of nonviolent criminals get rearrested for another crime.

If they stop committing crimes either because they are still in jail or dead, the crime rate would absolutely drop.

https://www.ussc.gov/research/research-reports/recidivism-am...

Depends how effective the enforcement is; but anyone who wants to repeat Pol Pot is someone to run from quickly, if they get anywhere near a position of power.