FORT LAUDERDALE, Fla. -- A judge ruled Thursday that Lionel Tate is competent to understand legal proceedings against him despite new revelations that Tate may be suffering mental illness from abuse as a child.

Judge Joel Lazarus said after listening to testimony from three psychologists that he "had heard nothing" to indicate that Tate was mentally incompetent.

Tate's lawyer said his client won't follow his legal advice, so he filed a motion to withdraw as the teen's attorney. Lazarus approved the motion Thursday.

Ellis Rubin said his decision is based on irreconcilable differences between him and his client.

"I regret that this 19-year-old young man will not abide by my 55 years of experience," Rubin said. "…I wish Lionel Tate the best of luck with his fifth attorney and may our paths cross again somewhere over the rainbow."

Tate told Lazarus that he intended to hire yet another private attorney to represent him.

Previously, Rubin filed a motion asking for Tate to be declared incompetent based on a letter Tate had sent a judge asking to withdraw a guilty plea to robbing a pizza deliveryman in May 2005.

Tate faces a return to prison for life if his probation is revoked for the 1999 murder of 6-year-old Tiffany Eunick when he was only 12. His lawyers initially claimed the killing was an accident caused when Tate imitated pro wrestling moves he'd seen on TV.

Tate has already admitted to possession of a firearm, and could face life in prison for that admission alone.

"I did conclude that he had the capacity to understand the range and nature of the penalties," said psychologist Donna Weiss, who examined Tate on April 11 on an order from Lazarus.

But Weiss did say that Tate could be suffering from "post-traumatic stress syndrome" because of abuse he allegedly suffered at the hands of his mother. Weiss testified that Tate told her he was severely abused from the time he was very young until about age 12 by Kathleen Grossett-Tate, who is a Florida Highway Patrol trooper.

"He could be suffering from a variety of mental illnesses," Weiss said, adding that Tate claims to suffer "nightmares and flashbacks" related to the abuse.

Neither Grossett-Tate nor her attorney, Michael Hursey, would comment about the allegations to reporters after the hearing.

Lazarus set a May 18 hearing to determine whether Tate will be allowed to withdraw his guilty plea in the pizza robbery case and possibly to impose a sentence.

Tate was the youngest person in modern U.S. history to receive a life sentence.