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
Back in 2000 I had a close skydiving buddy. He was an excellent competitive pool player and taught me how to play and I even went on to win a few tournaments.
Our friendship came to an end when my girlfriend broke up with me and he was in bed with her the very next day.
Out of curiosity I tried looking up his name about a year ago. Turns out he was living with a woman down in Tampa, Fl. She had lost a child previously and was dealing with major psychological issues… He came home to find she had committed suicide… And he killed himself because of it. This all happened way back in 2013. So he’s been dead a long time.