Nearly four years after a York Regional Police officer was killed, a teenaged boy is going on trial for murder.

It was a routine traffic stop back in June 2011 that became a murder the Crown alleged in a Newmarket court on Wednesday.

The incident claimed the life of York Regional Police Const. Garrett Styles and left the teenage driver paralyzed and confined to a wheelchair and on trial for first-degree murder.

The accused was just 15-years-old at the time, when he was pulled over by Styles for speeding. The Crown alleges the teen knew what he was doing when he tried to escape the traffic stop by speeding when Styles reached in the van to undo the driver’s seat belt. The Crown says Styles was holding on, draped across the teen driver.

The Crown also alleges the teen, who wasn't a licenced driver, had snuck out of his parent’s house and drove with their Dodge Caravan with three friends. The Crown says the accused had done this at least 20 times before.

Det. Const. Gordon Hebert, the investigator who led the reconstruction of the scene, testified, telling the jury the van crashed through several fences before going air borne twice off an embankment and rolling over. The court heard Styles was then thrown from out of the opened driver’s door and the van then landed on top of him.

Hebert was unable to determine how fast the minivan was travelling, but testified the brakes were never applied.

The trial is expected to last four weeks and at some point the jury will have a chance to see the minivan.

The court is expected to hear from one of the teens, who was a passenger in the minivan later this week.