Police have trimmed down the number of cases being examined under a project focused on unsolved murders and missing people cases.

Project Devote is a joint effort between RCMP and Winnipeg police.

Officers initially started off the project by looking at 84 different cases, before announcing Friday they've narrowed it to 28, comprised of eight missing person cases and 20 homicides.

Since October, 140 DNA samples have been reviewed with investigators examining clothing, vehicles and suspect information, looking for any links.

"At this point, there is no physical evidence to indicate that one person is responsible for more than one of these homicides, however there is a continuous assessment of (investigation) information, to determine if linkages exist,” said  Cpl. Miles Hiebert of the RCMP.

The oldest case being examined dates back to 1961.

"(Each) of the 28 investigations involved victims who were at high or extreme risk to become a victim of a violent crime," said RCMP in a press release.

Police said all those cases were chosen because the victims possibly lived a transient lifestyle, struggled with substance abuse, had mental health issues or worked in the sex trade.

Out of those 28 cases, 27 involve women while one involves a man.

Project Devote was launched in May 2011. An existing nine-person police task force was expanded with the addition of 15 more staff members.

RCMP said that while Project Devote has narrowed its focus to 28 cases, the remaining 56 cases that it initially examined continue to be investigated by other police officers.

Arrests have not yet been made as part of Project Devote, but police remain optimistic.

“I can tell the families this – never give up hope because there are hard-working, common-minded people that are committed to these projects and want to solve these crimes,” said Hiebert.

A tip line has been set up, with anyone having information encouraged to call 1-888-673-3316.

The Assembly of Manitoba Chiefs reacted to the police announcement Friday afternoon, saying they commend the work of Project Devote but also adding, "The project as presented to AMC is limited in scope and does not directly address the epidemic of missing and murdered indigenous women.”

Officials said at least 18 of the 27 cases being investigated that involve females involve aboriginal women.

The AMC said they would also like to be a part of a solution and be more involved in the project.

- with a report from CTV's Stacey Ashley