A dump truck driver who allegedly collided with a police cruiser after his brakes failed resulting in the death of a Los Angeles police officer last year pleaded not guilty Tuesday to gross vehicular manslaughter, reports the Los Angeles Daily News.

Roberto Maldonado, 46, of Pacoima was arraigned at the Los Angeles County Superior Court Tuesday for his involvement in the collision that killed Hollywood Division Officer Nicholas Lee, a 16-year Los Angeles Police Department veteran, and injured his partner.

A California Highway Patrol probe concluded that the truck's brakes failed because Maldonado did not properly maintain and inspect the truck, which is required by his carrier permit, prosecutors said.

Maldonado, who sustained critical injuries in the collision, faces up to six years in prison if convicted. He was released last year the day after he was arrested after posting a $50,000 bond.