Crown prosecutors are standing firm on not charging a Quebec police officer who was driving more than 50 kilometres per hour above the speed limit when he hit a family’s car, killing a five-year-old boy.

The Surete du Quebec officer was in an unmarked police car, speeding along boulevard Gaetan Boucher in Longueuil, Que., on Feb. 13, before slamming into the Belance family car as it made a left-hand turn.

Mike Belance and his daughter were badly injured in the crash. Five-year-old Nicholas Thorne-Belance died four days later in hospital.

While the police car had the right of way, critics said the officer’s high rate of speed may have been enough to warrant charges. But a spokesperson for the Crown prosecutors, René Verret, said that’s not enough -- police are authorized to go beyond the speed limit if needed.

An expert established at the time of the collision the officer's car was travelling 108 km/h in a 50 km/h speed zone. Just before, he had been travelling at 122 km/h.

"The speed itself is not enough to establish dangerous conduct," Verret said Friday at a press conference. "We can't conclude necessarily dangerous driving based on the consequences … in this case the death of a five-year-old."

The Crown confirmed that the police vehicle, and two other cruisers, were following another vehicle at the time of the crash.

"A police person was assigned to follow someone, and he was catching up on a target," said Verret.

Documents obtained by the newspaper La Presse show the police car was tailing a former director of the Liberal party of Quebec.

Verret said the officer tried to stop his black unmarked police car, as Belance made a left-hand turn at the intersection. The police officer told prosecutors he believed the car had stopped in the intersection and was waiting to cross. The officer involved in the collision was the second police vehicle to drive through the intersection.

Verret said Belance told investigators he saw a car travelling at high speeds at the opposite side of the intersection and that he should not have tried "his luck" and "he should have waited for his priority to turn."

A woman who had been sitting at a nearby bus stop witnessed the events. She told investigators that if she had been driving Belance's car she wouldn't have turned at the time.

Earlier this week, the Crown declined to lay charges against the Surete du Quebec officer involved in the collision. The Crown did not initially give the reasons behind the decision to forgo charges in the case, sparking an outcry from the family and the community.

On Friday, the Crown scheduled a meeting with the family to provide details about the decision.

Investigators with Montreal police, the force that took over the investigation after the crash, informed the family last week that the officer will not face charges.

Verret said that there were no external factors that could have contributed to the crash.

The officer was not responding to a call or to an emergency.

Relatives said the boy's parents were outraged when they heard the news, and were considering hiring a lawyer to determine what legal recourse they might have.