April Evil — John D. MacDonald

The stage was set. Harry Mullin had hit town first. But he had just made the FBI's Ten Most Wanted list, and he was a little nervous about being seen. With him at the rented house where they planned to case the job was a girl named Sal.

Then the Ace turned up. He'd been good in his day but had lost something in the guts department. But the last one in town was Ronnie. Ronnie had killed 12 men and two women in seven years and had gotten to like his job - maybe a little too much ...