Context : Randy Steven Kraft (born March 19, 1945) is an American serial killer known as the ``Scorecard Killer'' and the ``Freeway Killer'' who committed the rape, torture, mutilation and murder of a minimum of 16 young men in a series of killings spanning between 1972 and 1983, the majority of which had been committed in California. 
Answer : murder
For what crime was Randy Steven Kraft prosecuted?