Not just uncaught murderers, there are a lot of people who have killed without legally being considered murderers.
People who killed people in accidents such as driving accidents or hunting accidents
People who killed in self defense
Soldiers who killed enemy soldiers
Executioners
Police officers who have killed on duty
Doctors and nurses who have made mistakes that accidentally killed patients
I once gave a friend of a friend a condescending chewing-out after they did something hurtful.
Some time later our mutual friend informed me that they had died, but declined to tell me the cause of death.
Much later I discovered it was self-caused.
… Were my words too much? We spend our lives trying to be more effective communicators. What if we’re too effective when it matters most?