Prosecutors say a Canadian truck driver has pleaded guilty to a homicide charge for a crash on the New York State Thruway that killed a state trooper who had pulled over another driver.

Montgomery County District Attorney Jed Conboy says 66-year-old Gary Blakley of Ridgeway, Ont., pleaded guilty Wednesday to aggravated criminally negligent homicide and will be sentenced to 3 1/2 years in prison.

Conboy's rig crashed into the patrol car of 35-year-old Trooper David Cunniff near Thruway Exit 27 in Amsterdam in December 2013.

Conboy had pulled over a driver for speeding.

That driver was also injured in the crash.

In 2011, New York state instituted its "move over" law that requires motorists to slow down and move over if possible when approaching police and emergency vehicles pulled over alongside the road.