Lawyers and doctors for John W. Hinckley Jr. asked a federal judge Tuesday to grant the presidential assailant additional unsupervised visits to his mother’s home in Virginia.

Hinckley, 55, has been held at St. Elizabeths Hospital since being found not guilty by reason of insanity for shooting President Ronald Reagan, White House press secretary James Brady, D.C. police officer Thomas Delahanty and Secret Service agent Timothy McCarthy outside a Washington hotel in 1981.

Over the years, a federal judge has granted Hinckley more freedom from the hospital in anticipation of his eventual release. In 2009, at the request of Hinckley’s lawyers and doctors at St. Elizabeths, U.S. District Judge Paul L. Friedman allowed Hinckley to make a dozen unsupervised visits — each lasting up to nine nights — to his mother’s home.

Hinckley has used up those visits and “is unable to continue progressing with the therapeutic and transitional goals” without further trips, according to a court filing by his attorney, Barry Wm. Levine.

Levine and Hinckley’s doctors are seeking more visits until further hearings can be held delving into Hinckley’s treatment and progress. Levine could not be reached for comment.

William Miller, a spokesman for the U.S. Attorney’s Office of the District of Columbia, declined to comment.

Hinckley’s court filing, which comes on the eve of the 30th anniversary of the Reagan assassination attempt, was first reported by Legal Times.