The Halifax police cold-case squad has not solved a homicide since it was established 15 years ago, despite dedicated officers "working relentlessly" on the unsolved crimes.

"We have solved other files, but none that have been actually attributed to cold case at this time, but I am confident that we will," said Supt. Jim Perrin, the man responsible for the squad.

Perrin spoke to CBC News after Tom Martin, a retired investigator with the department, called on police management to put more resources into solving old homicides.

"The numbers speak for themselves," Martin said, noting there are 59 unsolved homicides on the force's books.

Halifax police public relations manager Theresa Rath said money "isn't an impediment" for investigating cold cases, noting that the Special Investigations Section, which includes the cold-case unit, has a budget of more than $3 million this year.

Jason MacCullough's slaying is one of 59 unsolved homicides in the Halifax area dating back to 1955. (Submitted by Halifax Regional Police)

Rath said the chief of police designated cold cases as one of the department's operational priorities in both 2014 and 2015.

"Our investigators are working relentlessly on numerous unsolved homicides and missing persons cases," she said.

She noted that over the past decade police have solved eight homicides approximately two years or more after they happened, but none can be attributed to the Cold Case Unit.

Perrin pointed out that 100 per cent of homicides this year and last year have been cleared.

Force won't discuss numbers

When the unit was first announced 15 years ago police said it would be composed of five members from the force's major crime unit with 12 to 24 years of police experience.

Today, the department will not disclose how many members are in the unit because "we don't discuss deployment" but it does say the unit has investigators and supervisor staff.

"We can assure the public that we're adequately resourced ... and have officers dedicated to current/recent and historic homicides," Rath said.

Cold cases challenging

Perrin said there are challenges with cold cases.

"When you look at those files they go back to the 1950s and the documentation that was done on a file in 1950 is a lot different than the documentation that's required now.

"So part of the task when cold case was put together was to go back over the years, try to find all the files, bring them all together, put them in some organized fashion and then prioritize them and start to investigate them," he said, noting that takes time.

He said the other realities of police work include turnover in the unit — officers who retire, get sick or get promoted.

Perrin said one of the biggest frustrations for investigators is that, "There are people who know what happened ... that could come forward and could solve these but for misguided loyalty or fear they choose not to."

He said one of the department's main priorities "is to give closure to the families that are left behind and justice for the people who have been murdered."