LIMA, PERU — A Peruvian police psychologist, revolted by the confessions he heard from an alleged mass murderer, admitted to using his belt to strangle the suspect in a jail cell.

The police psychologist could no longer listen to the murderer's "barbarities." Mario Poggi, a psychologist, told reporters Monday night that he choked Angel Diaz Balbin on Sunday to save humanity from the defendant's monstrous crimes.

Diaz Balbin was suspected of hacking up to eight people into remains he buried in different parts of the Peruvian capital since December, a homicide police spokesman said.

Poggi, who was mentally analyzing Diaz Balbin for the police, said he decided to kill the suspect when he could no longer bear listening to the alleged murderer's "barbarities."

At the end of a news conference Monday at Peru's detective corps headquarters, Poggi broke down in tears, saying, "I only wanted to save society from a murderer."

Poggi was being interrogated yesterday by homicide police who were preparing a report for the attorney general's office, according to the official news agency, Andina.