A former mental patient accused of slashing a Manhattan psychotherapist to death with a meat cleaver pleaded not guilty Tuesday to murder and other charges.

Court papers filed by the prosecution, meanwhile, say David Tarloff told police he was by sexually abused by his grandmother, and by a stranger when he was 5 years old.

The abuse claims could help form the basis of a possible insanity defense. In court Tuesday, his lawyer said Tarloff has made bizarre statements to his father such as, "I'm the Messiah; why are they doing this to me?"

Tarloff, 40, of Queens, is charged with first- and second-degree murder in the death of Kathryn Faughey, 56, in her Manhattan office on Feb. 12. He is charged with attempted murder and first-degree assault for allegedly attacking his former psychiatrist, Dr. Kent Shinbach, 70, when Shinbach tried to help Faughey.

Police have said Tarloff told investigators he had set out to rob Shinbach, who had him institutionalized 17 years ago.

Faughey's relatives were in court for Tarloff's arraignment Tuesday.

"We're all devastated, and we want to see justice done for our sister," her brother Owen Faughey said as he and other family members left court.

Police said in court papers filed Tuesday that Tarloff told them he had been in mental hospitals 21 times, the last time an involuntary commitment in Staten Island Hospital. He said left that hospital after three months but did not say when that was.

Police said Tarloff also told investigators he once woke up naked and found his grandmother "on top of him straddling him." At another point, Tarloff is quoted saying "that he was molested when he was 5 years old by an unknown male who approached him by the mail boxes and then took him to the back of the building."

Justice Charles Solomon denied a request by Tarloff's lawyer, Bryan Konoski, to move the defendant from a jail cell to a hospital psychiatric ward.

The judge also refused to order another mental exam. In February, two psychiatrists found Tarloff mentally fit in their evaluations.

Konoski complained that Tarloff had deteriorated mentally in jail largely because he had not been getting his psychiatric medication. He also said Tarloff had been socked in the jaw by another inmate and taunted by others who called him "Mr. Cleaver."

The judge said he would order medication for Tarloff and would direct that he be kept in protective custody. He scheduled Tarloff's next hearing for April 15.