Jose Martinez made the confession after he was arrested June 3 and charged with felony murder in the death of Jose Ruiz in March in Alabama, CNN reported Thursday.
"Killing people doesn't seem to affect him," said sheriff's Capt. Tim McWhorder in Alabama's
Martinez allegedly told police he killed his victims as enforcer for a Mexican drug cartel because they didn't live up to their obligations to the organization.
"I'm the guy that pays you a visit if you don't pay," he told police.
The slaying of Ruiz, though, was personal, CNN said.
The report said that while working together Ruiz insulted the girlfriend of a third man both men knew but didn't realize she was Martinez's daughter.
After two months, Martinez and the third man -- identified by investigators as Jamie Romero -- took Ruiz to the outskirts of Bankhead National Forest where Ruiz was killed, police said.