The Brooklyn resident who was convicted of killing four people last February pleaded guilty Tuesday to slashing a subway passenger following his violent killing spree.

Maksim Gelman, 24, admitted to an attack on subway passenger Joseph Lozito in Midtown Manhattan on February 12, 2011. He is expected to serve an additional 25 years in prison with his murders in Brooklyn.

The defendant's brutally violent crimes spanned two days and two boroughs, said District Attorney Cyrus R. Vance, Jr. We thank the New York City Police Department for their work in apprehending the defendant and bringing an end to his horrific crime spree.

Gelman threatened a man with a large knife while riding on a No. 3 subway train in Manhattan, according to his guilty plea. He then stabbed the man with the knife, causing lacerations to the victim's head, neck, face and arm.

He was apprehended by police after his crime at the Times Square subway station.  But Gelman's subway slashing was just the end of a horrific series of murders.

Dubbed the 'butcher of Brighton Beach,' Gelman was arrested last February after a 28-hour crime spree that began with a family argument over the use of his mother's car.

The stabbing spree started at his family's apartment in Brooklyn, where Gelman killed his stepfather, Aleksandr Kuznetsov. Hours later, he drove to the house of a female acquaintance, Yelena Bulchenko, and killed her 56-year-old mother. Police said he waited for the woman to return home and then stabbed her 11 times, reported CBS.

Gelman later stabbed a victim during a carjacking and then murdered pedestrian Stephen Tanenbaum, 62, by running him over with his car. Authorities said he also attacked a cab driver and another man during a carjacking, according to CBS.

The reason for Gelman's change in plea came after his psychiatrist said he couldn't argue his innocence by reason of insanity.

Gelman will be sentenced on February 15, 2012 for the attack in Manhattan.