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 met the guy who killed my best friend. At her funeral. He was her boyfriend. He got her addicted to drugs. Technically she killed herself by OD-ing, but had he never got her addicted she’d still be alive today. I couldn’t face him. He tried to talk to be and just walked away.