A burnt-out camper van belonging to the lifelong friends - Kam McLeod, 19, and Bryer Schmegelsky, 18 - was discovered on Friday along the highway in northern British Columbia.
Days before, two tourists were found shot to death 500km (310 miles) away.
Police say Mr McLeod and Mr Schmegelsky have since been spotted driving out of the province and are now suspects.
They were previously described by police as missing, with the implication that they may also be victims of the killer.
A third unidentified body was found near the young men's burnt out van.
In a news release on Tuesday, the Royal Canadian Mounted Police (RCMP) wrote: "Given these latest developments, Kam and Bryer are no longer considered missing. The RCMP are considering Kam McLeod and Bryer Schmegelsky as suspects in the Dease Lake suspicious death investigation and the double homicide of Lucas Fowler and Chynna Deese."