D.C. police yesterday filed bank robbery charges against a 22-year-old Washington man who they said robbed a Georgia Avenue bank on Monday and again on Tuesday, and then returned to St. Elizabeths Hospital where he had been committed after robbing the same bank two times before.

Police said that on consecutive mornings this week, John T. Crutchfield walked unarmed into the American Security Bank at 3500 Georgia Avenue NW, pretended to have a gun under his clothing, demanded money, and left with a total of about $2,000.

He had escaped July 9 from St. Elizabeths, where he had been confined for a year after having been found not guilty by reason of insanity of robbing the same bank in December 1980 and January 1981.

Police obtained a warrant for his arrest on robbery charges yesterday, and while they scoured the streets for him, learned that he had turned himself in Tuesday night to St. Elizabeths officials, who had obtained a bench warrant for him the day after his escape. At an arraignment in D.C. Superior Court yesterday, Crutchfield was ordered held without bond in the D.C. Jail. He is to return to court Friday following a mental examination.

Crutchfield told officials that he had lost the money he allegedly took in poker games, police said.

Robbery detectives yesterday were particularly incensed over the incident, both for the police manpower involved, and their contention that of the last 12 bank robberies in the District of Columbia, four have been committed by escapees from St. Elizabeths.

Capt. Thomas Novak, chief of the robbery squad, said: "These defendants that go to St. Elizabeths, committed there by reason of their insanity, eventually convince the psychiatrists that they are better . . . and they are gradually allowed more privileges until they gain the privilege of going out on the grounds, which allows them to escape. What it amounts to is a license to commit more robberies."

Dr. Harold Thomas, spokesman for St. Elizabeths, said yesterday that Crutchfield had "progressed to the point" that he was allowed daytime grounds privileges. "You never know if you can rehabilitate a patient unless you give him some responsibility," he said. "We can't keep everybody locked up all the time or we won't be able to rehabilitate anyone."

Another St. Elizabeths spokesman said that it "very unusual" for patients who walk away from the facililty to commit crimes.

Crutchfield had been a patient at the John Howard Pavilion for a year. The facility houses about 240 patients, most of whom, like Crutchfield, were found not guilty of crimes by reason of insanity.

Most of the patients are housed in locked, maximum security wards where they receive intense psychotherapy. They are generally allowed grounds privileges after an average of a year, according to hospital officials.

Police officials said yesterday that in the last three months three other escapees from St Elizabeths--Dennis Morgan, Ricardo Miles and Andre Burkley--have been charged with bank robbery. Morgan was charged with robbing the United National Bank at the Hechinger Mall on April 29, and Miles and Burkley were charged with robbing the Riggs National Bank at 900 F St. NW in June.

All had been sent to St. Elizabeths after having been found not guilty by reason of insanity of previous bank robberies.