Tony Lewis, a 26-year-old Arlington hairdresser, escaped from a mental institution in Falls Church March 18 and, apparently deranged by the drug PCP, led police on a car chase down Shirley Highway at speeds up to 100 miles an hour, police said.

The chase ended in Fredericksburg, Va., about 50 miles to the south, when police forced the stolen car Lewis was driving to stop and four state troopers wrestled him to the ground, according to police. Lewis was charged with 15 offenses, including four felonies, and the officers who locked him in a jail cell said he raved and ripped the clothes from his body.

Lewis, now in a Virginia mental hospital, will spend no more time in jail.

Authorities said he had been known as a quiet and religious man before apparently undergoing a personality transformation after smoking a marijuana cigarette laced with PCP on March 10. His subsequent behavior led to his hospitalization in Falls Church that preceded the chase.

Fairfax and Fredericksburg prosecutors decided to drop the charges filed in their jurisdictions following the chase, leaving two felony charges of hit-and-run driving and a misdemeanor charge of car theft in Prince William County.

Lewis pleaded innocent by reason of insanity in Prince William Oct. 2 based on the argument that he was suffering from a PCP-induced psychosis.

Charles Zauzig of Woodbridge, Lewis' attorney, said the case presented a legal problem because under Virginia law someone who becomes intoxicated by a substance he has voluntarily consumed cannot claim innocence because of that intoxication. Zauzig based Lewis' insanity defense on the argument that the psychosis induced by the PCP remained after the intoxication wore off.

The prosecution agreed that Lewis was insane on the day of the chase and that he was not responsible for his acts, according to Assistant Prince William Commonwealth's Attorney William Hamblen.

Prince William Circuit Judge Percy Thornton accepted the insanity plea, ordered Lewis to Central State Hospital for examination and said he would be released when found not to be a danger to himself or others.

"I don't think he will be in there long," Zauzig said last week. "He's a good kid. He's over the episode. . . . You don't believe it's the same person described to you that day."