A Quebec prosecutors' decision not to charge an speeding undercover Surete de Quebec provincial police officer for an accident which killed Nicholas Thorne-Belance, 5, in Longueuil last February has created a stir on social media.

Many Facebook members have denounced the decision by placing a photo of the child as their profile image while others have also written notes to express their outrage.

"These idiots don't understand. An innocent child died from his injuries due to this officer. Where is Quebec's ***** justice system?" wrote one.

Meanwhile a petition demanding "that criminal charges be brought against the police officer involved in the crash" rapidly attracted 1,000 signatures on a dedicated page Saturday morning. Facebook users sent photos of their children holding a sign reading "luckily it wasn't me" on another dedicated page.

Quebec Crown prosecutors held a press conference Friday to explain why there will be no charges laid against an undercover SQ police officer who was driving 122 km/h in a 50 km/h zone, leading to an accident on February 13 that killed Nicholas in Longueuil.

The conference was called after documents obtained by the newspaper La Presse show the police car involved in a high-speed crash was tailing a former director of the Liberal Party of Quebec as part of a mission for the UPAC anti-corruption squad.

The boy died after an unmarked Surete du Quebec police car rammed a car that was making a left-hand turn.

The crash badly injured Mike Belance and his daughter and killed his five-year-old son Nicholas Thorne-Belance.

Following an investigation by Montreal police, this week Crown prosecutors decided not to file charges against the officer and initially refused to tell the family why. Now La Presse is reporting that documents reveal the SQ car was one of four unmarked vehicles working for the province's anti-corruption unit UPAC, and that the officer who caused the deadly collision was following Robert Parent.

Parent was the Liberal party's director for several years and is apparently being investigated for breach of trust with regards to party financing.

The SQ car did not have its lights flashing or siren blasting at the time of the crash, and until this report there has never been any indication the police officer was doing anything requiring any urgency.

The Crown finally met the Belance family on Friday morning to discuss the case and the family is expected to speak to reporters later.

Verret explains why no charges were laid

Prosecutor René Verret who serves are Director of Criminal and Penal Prosecutions held a press conference late Friday afternoon to shed more light on the decision not to file criminal charges.

"It's a difficult process. We are prosecutors but also human beings and we must consider the interests of the public but also know the circumstances surrounding the event," he said. "The families are being made aware and we are approaching this process with respect to the families who are going through a difficult time."

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.

Belance - the father driving the other vehicle - told investigators that 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.

Verret said that the speed wasn't the only element to consider when evaluating the events.

Verret said that under questioning the father often drives the same route and turned green before the light began flashing, which gives priority to such turns.

"The child's father said in his statment that he should have waited for the flashing green rather than taking his chance turning at that moment," said Verret. The father attempted to slow down after noticing the fast-moving car about one second before impact.

Verret said that such undercover officers are highly-trained and are permitted to act in a dangerous way when circumstances warrant.

"The father did not know that it was a police car," noted Verret. "Undercover police tailing suspects do not put sirens on their cars because they can't risk being spotted by their targets."

The family has hired a lawyer and is exploring their legal options. They are no longer pubicly discussing the incident.

Couillard distances himself

Premier Philippe Couillard distanced himself from the affair when asked about the issue following a meeting with Ontario Premier Kathleen Wynne Friday afternoon.

“I don’t see the relevance of your question with the events being discussed today,” said Couillard. “I remind you that those events took place in February 2013 and I became leader of the Quebec Liberal Party in March 2013.”

Quebec Justine Minister Stéphanie Vallée, who was with Couillard in Toronto, also appeared reticent to invoke her powers to demand an independent review of the decision not to press charges. “Those are exceptional steps and for the moment it’s way too early for that,” she said.

Parti Quebecois Justice critic Alexandre Cloutier said that it was not too early for such a review. “She is the chief prosecutor of Quebec, it’s up to her to intervene and to demand an external inquiry or at least an external review by an independent prosecutor, so we can look at the proof,” said the Lac St. Jean MNA.

The opposition CAQ party was also critical. “We hear all sorts of things when we’re on the ground with citizens who say ‘we know that they’re police officers,” said Marc Picard, the Chutes de la Chaudiere MNA at a press conference in Quebec City Friday.

Picard also complained that a bill meant to create an independent bureau of inquiry has been passed by has still not been created. “Police must not investigate police,” he said.

-With a file from The Canadian Press