MONTREAL -- The Sureté du Quebec will significantly hike the number of officers assigned to its cold case squad in the coming months as it aims to tackle a backlog of unsolved slayings dating back more than 50 years.

The unit's membership will increase to nearly 30 from five and will have a presence in the Montreal area and Quebec City, a spokeswoman for the force said Monday

Lt. Martine Asselin explained that regular investigators often have to respond to breaking crimes or urgent cases, meaning unresolved killings head to the back burner.

That will change with a beefed-up staff committed solely to those unresolved cases.

"Now they will work full time on these cases," Asselin said. "They will concentrate 100 per cent on these cases. That'll permit us to move...forward."

The unit will have plenty of work as there are currently about 750 unsolved cases in its jurisdiction, dating back to the 1960s.

"For the last 10 years, we brought back (centralized) all the unsolved files to the cold case unit (near Montreal)," Asselin said. "And in the past two years, we went through all of them and came up with a (blueprint) of what we could do to have an ending in those investigations."

Nearly two-thirds are organized crime cases, but the unit will focus on those involving women, children and the elderly, Asselin said.

All Canadian police forces handle cold cases differently: some have a handful of police officers dedicated to the cases while others leave it up to homicide detectives alone.

Quebec provincial police, which will have among the largest units, say they found benefits in having a bigger group working on a case -- like the high-profile disappearance of Cedrika Provencher, a young Quebec girl who vanished from near her home in 2007.

In December 2015, her remains were discovered in a wooded area and, to date, there have been no arrests in her disappearance and slaying.

When the squad was founded in 2004, it wanted to take advantage of relatively new investigative techniques like DNA profiling.

Asselin said investigators found that witnesses or tipsters are more willing to talk as time passes.

She also said social media could be a new tool for the revamped unit.

"Someone who knew something who didn't talk, maybe sometimes sitting behind a computer is more likely to (get them) share the information," she said.

The unit currently solves a few crimes a year on average but is hoping to dramatically increase the ratio.

"More investigators will hopefully help us arrest someone and give some answers to the families," Asselin said.