John Hinckley's tendency to lie and his isolation increase the risk that he presents a new danger to society after 30 years of confinement for shooting president Ronald Reagan, a psychiatrist told a federal judge.

The judge is reviewing Hinckley's case to decide whether to expand the conditional release rights of the 56-year-old man, who was declared insane during a 1982 proceeding.

The ultimate goal of the new proceeding is to determine whether Hinckley should be allowed to live full-time with his mother at her home in Williamsburg, Virginia.

Raymond Patterson, former director of forensic services at Saint Elizabeth's Hospital, where Hinckley is confined, testified for the government, saying the repeated lies and isolation of the patient are "worrying" because they "increase the risk factor of becoming a potential danger to himself and to others."

He said Hinckley "was isolated prior to 1981. It was one of the factors to this killing attempt" against then-president Reagan on March 31, 1981 outside a Washington hotel.

He added that Hinckley still refused social activities offered to him.

"Isolation is a risk factor," Patterson said. "There is concern that if Mr. Hinckley becomes isolated, he could become more depressed and psychotic."

The psychiatrist mentioned two of the times Hinckley had lied, once saying he went to see movies during visits to his mother in Williamsburg that he had not really seen.

Another time he said he often drove a car in Williamsburg, Patterson said. Secret Service agents who followed Hinckley testified the truth was that his mother drove him around.

"He lies smoothly," said Patterson, who testified that he interviewed Hinckley and his doctors.

"We need to trust him," Patterson said. "If he's not doing his part, there's no reason to give him more time" out of the hospital.

Federal Judge Paul Friedman asked what was planned if Hinckley's mother, 86, was no longer around after the patient regains his freedom.

"His mother is not going to live forever," he said. "At some point, he's going to be on his own."

Patterson replied: "There's nothing specific in the plan if his mother becomes unavailable."

Hinckley wounded Reagan by shooting him in the chest to impress actress Jodie Foster, with whom he was obsessed.

Since 2009, he has been granted 10 consecutive days per month of freedom to visit his mother. His lawyers asked that Hinckley's release rights be expanded first to 17 days, then 24 days per month.

Eventually, his doctors want him to be released permanently to live as an outpatient with his mother.