The family of a five-year-old boy is considering its legal options upon learning that a police officer will not be charged after his unmarked cruiser slammed into their car, killing the child.

The boy died four days after an unmarked Surete du Quebec cruiser slammed into his father's car as it was making a left-hand turn on a residential street in Longeuil in February.

Investigators with Montreal Police, the force that took over the investigation, informed the family last week that the officer will not face charges, even though he was speeding at the time of the collision.

The officer was travelling 122 km/h right before the accident and tried to slam on the brakes, investigators told the boy's family. The cruiser hit the family's car at a speed of 90 km/h.

The speed limit on the street was 50 km/h.

The officer was not responding to a call or to an emergency, CTV Montreal's Maya Johnson reported Wednesday. The Crown does not have to give its reasoning when it decides not to lay charges.

The boy’s parents did not want to speak to the media on Wednesday. However, relatives said they are outraged, and believe that a civilian would have been charged in the case, Johnson reported.

The parents are considering hiring a lawyer to determine what legal recourse they may have.

The boy's aunt, Islande Belance, said the entire incident is "really unfair."

"Somebody just took his life," Belance said.

She recalled the boy as "an angel," who was "full of life."

With report from CTV Montreal’s Maya Johnson