MIAMI (AP) _ A man who said he was possessed when he stabbed his girlfriend 111 times, cut off her head and threw it at a policeman while walking nude on a street has been acquitted of murder but found to be insane.

Alberto Mesa, 24, was turned over to the Florida Department of Health and Rehabilitative Services for mental treatment after being acquitted Monday in a non-jury trial in Dade County Circuit Court.

Under state law, the department must report to the court on Mesa's condition after six months and once a year thereafter. He could remain hospitalized involuntarily if there is enough evidence to show he suffers from mental illness and that he will inflict harm on himself or others.

Mesa was arrested March 2 when a police officer spotted him walking nude down a street, carrying the head of 18-year-old Dina Tormos.

''Arrest her. I killed her,'' Mesa yelled as he tossed the head at the officer, according to evidence. ''She's the devil. She tried to kill me. Do you believe in Jesus?''

In a videotaped interview with psychiatrists afterward, Mesa said: ''I know the only thing I'm guilty of is loving God. Something got in me. I felt possessed. Something was telling me to do these things.''

In the psychiatric interviews, Mesa said he had once experimented with LSD, but had given up all drugs and sex during Lent.

He said he ''was thanking God for all the things he was doing for me. Things were going real good for me.''

Then, he said, ''I started seeing things in shadows ... on the roof ... angels and things and faces. I got scared.''

Mesa said he didn't remember stabbing Miss Tormos in his apartment, cutting off her head, taking off his blood-drenched clothes or carrying her head down a residential street.

''I still don't believe it happened to me,'' he told his interviewers. ''She was a good girl. I couldn't do nothing about it.''