The boy started by killing a gas station attendant. Soon thereafter, he killed his girlfriends' family, including her two-year old sister.

They went on to kill (and sometimes mutilate)
many more innocent people.

Charles Starkweather and Caril Fugate were the inspiration for several
movies... including

Kalifornia and Natural Born Killers.

Charles was executed for the crimes in 1959.
Caril was imprisoned and released in 1976.