Quebec City police say a "mistake with two facets" is responsible for under-reporting the number of hate crimes and related incidents in 2018, the year following the deadly mosque shooting.

On Jan. 29, 2017, six men were killed and another five injured after a man armed with a rifle and a restricted semi-automatic gun entered their mosque after Sunday evening prayers and opened fire. Alexandre Bissonnette is serving a life sentence with no chance of parole for 40 years for the killings.

"We recognize that we made a mistake, and processes have been put in place so those mistakes don't happen again," said a communications officer for the Quebec City police service (SPVQ), Const. David Poitras, about the erroneous report.

The SPVQ granted the interview with Poitras six weeks after CBC asked why Statistics Canada had recorded 89 hate crimes and incidents in the city in 2018, while the police service proudly announced in January that the number of hate crimes had plummeted in 2018 to just 27 incidents.

Hundreds of Quebec City residents turned out in March at rally against hate and racism in the wake of the shootings in New Zealand. (Radio-Canada)

Poitras said that for an unknown reason, the SPVQ sent Statistics Canada a tally of the incidents initially flagged as possibly motivated by hate, instead of a list of all those which the service investigated.

Another mistake was made during the "manipulation" of data in response to a request from Radio-Canada for an accounting of 2018 hate crimes, ahead of events to commemorate the victims on the second anniversary of the mosque attack.

Poitras said the SPVQ has checked to make sure the person responsible for compiling that data erred accidentally and didn't release erroneous figures on purpose.

"Instead of seeing 27 hate crimes and incidents, there should have been 60," said Poitras.

Even though the number of incidents more than doubled from what was initially reported, the trend is downward, with the number of hate crimes on the decline for the first time since 2015.

In 2018, the crimes included two assaults with a weapon, eleven threats and 11 assaults.

Between 2016 and 2018, Muslims were targets of the incidents between 31 and 50 per cent of the time, even though they represent less than one per cent of Quebec City's population.

Why no questions asked about discrepancy?

Maxim Fortin, co-ordinator of the Quebec City chapter of the Ligue des Droits et Libertés, said the city's police service can be 'naive' about hate crimes.

A Quebec City anti-racism activist, Maxim Fortin, said incorrectly calculating and misreporting the number of incidents motivated by hatred shows a lack of competence and a certain "naïveté" on the part of the municipal police service.

"The SPVQ should be more cautious," said Fortin, who co-ordinates the Quebec City chapter of the Ligue des droits et libertés.

"They were not very vigilant, considering the Quebec City region is prone to hate crimes [and] conservative-thinking, ultra-nationalist movements."

Fortin said groups like his need correct data to assess what has to be done in terms of prevention or protection.

It's problematic, as well, he said, that police didn't question the apparently dramatic drop in hate crimes until CBC News pointed out the discrepancy with the Statistics Canada numbers, six months after the SPVQ released its own data.

Instead, the SPVQ told Radio-Canada in January that its investigators had been so sensitized to hate crimes after the mosque shooting that the police service had been able to prevent them from occurring.

In his interview with CBC, the SPVQ's Poitras could not explain what the police service had meant by that.

Poitras said the service does consider hate crimes to be among the most serious kind of crimes — because they can affect dozens,"even hundreds" of people — and that is why the force's major crimes unit is in charge of investigating anything hate-related.

Since 2017, about 180 of the force's 800 officers have received special training in what constitutes a hate crime.

Poitras said there is no reason for people to lose trust in the police because of a mistake in "numbers," because what is important is that officers are doing their jobs properly when they investigate hate crimes.