Published: Oct 05, 2010 3:51 PM EDT
Updated: Oct 05, 2010 12:51 PM EDT

GAINESVILLE, Fla. (AP) - A gunman with a history of mental illness shot his father to death, then drove through his Gainesville neighborhood on a 13-minute, three-mile shooting spree that wounded five others before he killed himself, police said Tuesday.

Clifford Miller Jr., 24, killed his 52-year-old father, Clifford Miller Sr., before he went on his rampage and fired multiple rounds from a .38 caliber revolver at each spot, Gainesville police Cpl. Tscharna Senn said.

"He did have a relationship with the remaining victims," whom she identified as men. "Right now, we do not have a motive."

The younger Miller shot himself in his red pickup truck. The gun was found with him.

Miller, who previously worked as a dishwasher at a Mexican restaurant in Gainesville, had a lengthy criminal history, court records showed.

When Miller was 19, he was found guilty of cocaine possession and violated probation. When he was about to return to court, he wrote the judge a letter.

"My family and friends are so prowed (sic) of me because I have been working for a year," he wrote in 2006. "I beg of you to drop the case so I can finish being successful in life."

Every year since, Miller was charged with either a traffic offense or other crimes. In 2006, he grabbed and spit in the face of an ex-girlfriend and was charged with simple battery. She refused to press charges. In 2007, he was found guilty of breaking into an ex-girlfriend's house and roughing her up.

In 2009, he assaulted another woman, a friend, but she refused to press charges.

Also in 2009, he was charged with reckless driving, driving while under the influence of drugs or alcohol and refusing to sign or accept a traffic citation. In that case, an Alachua County judge declared him incompetent.

As some of the conditions of his release from jail, Miller was required to take medication and undergo psychiatric treatment.

It was unclear what touched off Monday's shooting spree.

The first 911 call was at 4:03 p.m., followed by several others.

The last call was to the Alachua County Sheriff's Office at 4:16 p.m. That turned out to be the gunman.

Another shooting location was discovered an hour later, but officials said it occurred within the 13-minute period.

The wounded were being treated at Gainesville area hospitals, Senn said.

Among the victims: Cedric Joiner, 36, Lloyd Dunn, 67, Paul Anthony Sr., 43, and Vincent Saller, 43. They are all listed in critical condition. Anthony Mitchell, 44, is in fair condition.

Gainesville, in the north-central part of the state, is home to the University of Florida. There was no link between the school and the shooting, police said.