Broward County (Fla.) Sheriff Al Lamberti reported Thursday that career criminal Michael Mazza has confessed to killing Dep. Paul Rein Thursday.

Mazza, 40, is charged with first-degree murder in the slaying of Rein, a 76-year-old custodial deputy who was working alone transferring Mazza from jail to court.

Witnesses say that Rein and Mazza were in the transport van when Mazza convinced Rein to stop the van and let him out. One witness told the Miami Herald that Rein helped Mazza out of his wheelchair and was walking him around the side of the van when Mazza grabbed Rein's .38 revolver. Mazza then shot the deputy and left him to die in a parking lot.

"Dep. Rein was taken advantage of by a predator," Broward County Sheriff's Office spokesman Elliot Cohen said Thursday. "He was willing to help someone, and Mazza took advantage of the deputy's good nature and murdered him."

Mazza escaped in the van but ditched it. He then hitchhiked to Hollywood, Fla., where he was captured in a pawn shop still in possession of the deputy's revolver.

The sheriff's department is facing questions of why the deputy was working alone, especially considering his advanced age.

Mazza is a career criminal with a 17-year record. He is 5-foot-9, weighs 210 pounds, and was already serving a life sentence. He was being transferred to court to face trial on bank robbery charges.

When questioned why a grandfather was transporting dangerous convicts by himself, Rein's supervisor Col. James Wimberly told the Miami Herald, "We can't discriminate against folks because of their age."

Other supervisors told the Herald that Rein was in "outstanding physical shape."

Rein joined the department in 1987. He passed a certification physical in 2003 when he returned to work after a three-year break.

Two of Rein's children have also served in law enforcement: Richard Rein, retired from the Davie police, and stepson Christopher Beroldi, currently an officer with the Coconut Creek police.