An Ottawa police officer will not face charges after a crash in downtown Ottawa killed a 54-year-old man in October 2013.

Ontario’s Special Investigations Unit said there were no reasonable grounds to lay charges after a six-month investigation that involved seven witnesses, GPS data from the police cruiser and public cameras.

The SIU investigation discovered the female police officer made a U-turn to follow a Honda Civic at about 3:50 a.m. on Oct. 2, 2013 with the emergency lights activated. The driver did not stop and collided with a Kia Rondo, killing the driver.

“Evidence collected by the SIU indicated that the subject officer’s cruiser was slowing down and no closer than approximately 200 metres from the collision between the Honda Civic and the Kia Rondo,” according to SIU director Tony Loparco.

That evidence means the vehicles were not involved in a police pursuit.

Driver faces several charges

Police said Alain Seguin was found with vital signs absent and taken to hospital, where he was pronounced dead soon after.

Alain Seguin

Alain Seguin, 54, was killed by an alleged impaired driver in an early morning crash in downtown Ottawa on Oct. 2, 2013. (Facebook)

Seguin was engaged, had two daughters, two stepdaughters and three grandchildren, according to his obituary.

Adam Patrick Prevost, who was 19 at the time of the crash, faces three charges including impaired operation of a motor vehicle causing death, criminal negligence causing death and failing to provide a breath sample.

The charges against Prevost allege he was “driving at a high rate of speed” and ran a red light before the fatal crash.