Broward County Sheriff Al Lamberti said Michael Mazza - already serving a life sentence for armed robbery - may have had accomplices who ambushed 76-year-old Paul Rein as he drove Mazza to court for his trial on a separate robbery.
Mazza, 40, was arrested at a Hollywood pawn shop shortly after noon, about four hours after Rein was found shot and bleeding in a parking lot, Lamberti said.
The two were alone but separated by a partition in a medical van, and Mazza was wearing handcuffs, authorities said.
Mazza, dressed in a suit and tie for court, was being transported in the medical van because he had complained of a bad back. Lamberti said it was a routine transport, done "hundreds of times a day."
The van was later found empty 20 miles away in a Fort Lauderdale restaurant parking lot.
Traffic backed up for miles and schools were placed on lockdown as authorities launched a manhunt after the shooting. Investigators still were trying to figure out his steps, but a man who refused to give his last name said he met Mazza at another pawn shop, and Mazza asked him for a ride.
Mazza wasn't wearing handcuffs, said his name was Tony and said he didn't care where they went, the man said.
"He said he just had an argument with his wife, and he left from up state," said the man, who gave his name only as Mark. "He was sitting down at a store, all exhausted and everything ... and his leg was messed up, hurting."
They went to a soup kitchen and got something to eat, the man said, and then to the Hollywood pawn shop. Mazza stayed in the car, and when the man went inside, he saw Mazza's picture on television and realized his passenger was a fugitive.
"I freaked out," he said.
He and the manager called 911, and police arrived.
Mazza was on trial in connection with a Feb. 28 bank robbery. After robbing a Bank of America in Coral Springs, Mazza led police on a short chase before he crashed his car into another vehicle, injuring himself and two others, authorities said.
Mazza's attorney, Maurice Graham, requested a mistrial Wednesday morning in court, where he and prosecutors listened to radio updates about the search for Mazza. Graham did not immediately return a phone message or e-mail from The Associated Press.
A person who identified herself as a relative of Rein's declined to comment when reached at his home. Authorities said he spoke to his wife by phone 10 minutes before he was shot.
Rein's ex-wife, Mollie Meyers, described him as a 5-foot 7-inch "little strong guy" who retired from the U.S. Postal Service at age 55 and began a second career in the sheriff's department.
She said she and Rein split up seven years to the day he was killed, and both remarried after being wed for 49 years. They had two grown sons, one of whom recently retired as a police officer in Davie. A stepson works for the Coconut Creek police department.
"It hasn't sunk in yet," Meyers, 75, said of Rein's death. "I couldn't tell you how I feel."
Rein served as a Broward deputy from 1987 to 2000; the department lured him out of his second retirement in 2003.
Meyers said she rarely worried about Rein's safety because his job involved dealing with inmates, not working the streets. However, she said her ex-husband should not have been alone with Mazza, whom she called a "terrible person."
"There should have been another deputy with him," Meyers said.
Rein's file includes numerous letters of commendation, including one from an inmate who said Rein "treated me with a little respect and dignity" when the deputy transported him in 1997.
Rein is the fourth South Florida law enforcement officer and the third Broward deputy shot in the last three months.
Deputy Maury Hernandez was shot in the head Aug. 6 during a traffic stop. He was released from the hospital Oct. 25. Sergeant Chris Reyka, 51, was fatally shot as he was looking for stolen vehicles behind a drug store Aug. 10. His killer is still being sought.
In September, Miami-Dade County police officer Jose Somohano was fatally shot by a gunman who ambushed him and three other officers. The suspect was killed by officers hours later in Broward.