A Sûreté du Québec (Québec Provincial Police) vehicle in the snow. The Québec Provinicial Police are substantially expanding their cold case squad from five to 25 investigators in an effort to solve a group of roughly 750 unsolved cases. (Photo: Courtesy of the Québec Provincial Police via Facebook)

Homicide cold cases never go away. Some may be solved, generating big headlines and an occasional arrest years after a victim has been laid to rest. But every year, more unsolved deaths pile up, no matter what agency is investigating. As detectives have said, you can’t solve every one out there.

But now the Québec Provincial Police are going to try and go after the most elusive cases of the last few decades.

The authorities are increasing staffing on their cold case squad from five persons to 25 detectives—and they are going to be looking at a group of roughly 750 cases full-time, trying to crack some of the toughest remaining mysteries in the province.

The Sûreté du Québec told the Toronto Star and the Journal de Québec that the roughly 750 case total is made up of approximately two-thirds organized crime cases. But of the total case load, they plan on focusing first on the unsolved crimes in which the victims are women, children or the elderly.

The cold case squad was founded in 2004. Originally intended to focus on the advent of DNA identification, the detectives have also found the passage of time can help get members of the public to offer key tips that help solve a case.

“Experience has shown that, even after several months, or years in certain cases, the processing of new information provided by the public can assist in solving cases that families, witnesses, and even the police, believed were unsolvable,” the squad says on its site.

The latest staffing boost, according to Canadian media accounts, was spurred by the notorious disappearance and homicide of Cédrika Provencher, who vanished in 2007.

The 9-year-old girl was riding her bike on July 31, 2007 in the city of Trois-Rivières as she searched for a small dog who had been lost. But she did not return home—and despite a massive search by family and then regional police, days and weeks and then years passed without any sign of her. Eight years later, bones were found by hunters in a wooded area about 15 kilometers away—and they were quickly identified as the remains of Provencher.

After those remains were discovered in December 2015, authorities made the decision to boost cold case staffing.

Homicide clearance rates in the United States generally estimate about a third of killings go unsolved every year, leading to a mounting cumulative case load.