Would-be assassin John W. Hinckley Jr. remains deceptive and isolated – risk factors that should be weighed in deciding whether to grant him more freedom from his psychiatric hospital, an expert testified Wednesday.

Dr. Raymond Patterson, a witness for the government, testified in hearings that will help determine whether a federal judge should grant a request from St. Elizabeths Hospital to extend Hinckley’s visits to his mother’s hometown of Williamsburg and to give it the authority to release him there full-time.

Federal prosecutors oppose the proposal and have argued that Hinckley remains a risk because he is deceptive and not ready for more privileges.

Patterson, a psychiatrist who interviewed Hinckley and his doctors, said the presidential assailant lied to him and his treatment team about having seen movies in Williamsburg that he had not attended last year.

He was also deceptive when he told his therapist that he was driving most of the time when in Williamsburg. Secret Service agents who watch the 56-year-old Hinckley observed his mother driving him around most of the time.

He also did not tell his therapist in Williamsburg that he had gotten engaged last year to a former mental patient at St. Elizabeths.

Hinckley “lies smoothly,” Patterson said.

“That is what Mr. Hinckley does – he tells people things and you don’t know when he is lying,” Patterson said, adding that treatment providers ”have to be vigorous in getting information from Mr. Hinckley because he doens’t volunteer a lot.”

Such behavior could prove problematic if Hinckley spends more time in Williamsburg and is eventually released there because his doctors would have to rely on his word about many of his activities.

Though Hinckley has a social life at St. Elizabeths, he has not engaged in many social groups or made any friends in Williamsburg, Patterson said. In addition, he has rejected outings proposed to him by his treatment providers, Patterson said.

Prosecutors say Hinckley has not taken sufficient steps to integrate himself into the Williamsburg community and worry what might happen when his 86-year-old mother dies or “becomes unavailable.”

“Isolation is a risk factor,” Patterson testified. “There is concern that Mr. Hinckley could become isolated and could become more depressed and psychotic.”

Before shooting and nearly killing President Reagan on March 30, 1981, Hinckley lied repeatedly to his parents about his activities and was deceptive with his psychiatrist. A loner, the 25-year-old shot Reagan and three other men in the delusional hope that he might impress movie actress Jodie Foster, whom he had been stalking.

The proceedings started in January with testimony from Hinckley’s doctors, treatment providers and family members. They testified that they believe he is ready for expanded privileges and needs that freedom to grow in therapy.

The hospital is seeking to expand Hinckley’s 10-day visits to Williamsburg to as long as 24 straight days and to have the power to release him there full-time. They would also like Hinckley to be allowed to drive a car unaccompanied by other passengers.

On Monday, prosecutors began their case with the testimony of two Secret Service agents who said they watched Hinckley enter bookstores on two occasions and peruse shelves that contained books about President Reagan, his attempted assassination and other assassinations. U.S. District Judge Paul L. Friedman could issue an opinion at anytime after the hearings conclude, perhaps as early as next week.

Read more: The Post’s crime coverage