John Hinckley, who attempted to assassinate US president Ronald Reagan in 1981, was granted unconditional release Wednesday by a Washington judge, six years after he was freed from a psychiatric hospital.

The court ruled that after decades of treatment and psychiatric reviews, Hinckley no longer presented a threat and conditions set on his life after release would be lifted on June 15.

Hinckley, 67, shot Reagan and three others with a revolver outside a Washington hotel on March 30, 1981, saying he wanted to impress actress Jodie Foster, whom he became obsessed with after watching the film "Taxi Driver."

All four survived, though Reagan press secretary James Brady was left partially paralyzed and forced to use a wheelchair.

At trial in 1982, Hinckley was declared not guilty on grounds of insanity, and placed into St. Elizabeths Hospital, a psychiatric institution in Washington, for 34 years.

He was released in September 2016 but required to live with his elderly mother in a gated community in Williamsburg, Virginia under a long list of restrictions.

Those included controls on his movements and monitoring of his electronic devices and online accounts.

He was also forbidden to contact Foster or travel to any area where a current or former president, vice president or member of Congress would be present.

He also could not speak to the media or post any writings or memorabilia on the internet or display them in person without authorization. 

A government report on his status filed to the court on May 19 said his mental health had "remained stable" and that his psychiatric illness had been in "full and sustained remission for decades."

"He has not reported or exhibited any psychiatric symptoms consistent with a mood, anxiety, or psychotic disorder," it said.

"Characteristics associated with his narcissistic personality disorder, for example self-absorption and grandiosity, continues to be significantly attenuated compared to observations made in the 1980s."

In recent years Hinckley has undergone music therapy and began playing guitar and singing original folk-country songs on YouTube and other music sites.

In December he announced he would release a CD of his music.