A mentally ill man who killed a Los Angeles airport policeman during a carjacking has been sentenced to life in prison without chance of parole.

William Sadowski was sentenced Friday for the April 2005 carjacking and murder of Tommy Scott.

The 51-year-old former aerospace engineer has bipolar disorder but a jury ruled he was legally sane when he stole Scott's patrol car after the officer stopped him near Los Angeles International Airport.

Scott held on for a quarter-mile and was decapitated when the car struck a fire hydrant.

Sadowski told investigators he'd only planned to crash and kill himself. In court Friday, Sadowski said he remembered Scott fighting for the car but little else. He apologized for killing him.