Transcript for New images show couple before their deaths in Canada
We get the latest in the killing of a young American woman and her boyfriend in Canada as police try to determine if there is a connection to the death of another man hundreds of miles away. Matt Gutman is tracking the case and Canadian officials warning tourists to be vigilant. Reporter: That's right, George. This comes right in the peak of tourism season in Canada. Last night police revealing that stunning possible link between the murder of that couple we've been following, the mysterious death of a still unidentified man and the disappearance of two teens, all in northern British Columbia. That newly released surveillance video showing chynna Deese and her boyfriend Lucas fowler at this gas station. You can see Deese cleaning the van's windows. Lucas pumping gas. At one point the two sharing that sweet embrace all about a day before they were brutally murdered. We can now confirm that chynna and Lucas were the victims of gun violence. I don't know how anybody could live with them after doing what I saw. Reporter: He said the bodies were left in the ditch by the side of the road. The advantage's side doors left open. Back window shattered but stranger yet, he says, their bodies arranged almost identically. Another road worker saw a bearded man talking with the couple earlier. To me he looked frustrated. Reporter: Police basing this sketch on her description eerily similar to another sketch based on the image of an unidentified man police found dead 300 miles away four days later. Overnight Canadian police revealing the couple's murder and this third mysterious death in British Columbia could be connected. It's unusual to have two major investigations under going of this nature in northern bc at the same time. These could be linked. Reporter: They discovered that bearded man's body while discovering a burning camper, driven by 19-year-old cam Mccloud and 18-year-old breyerer mcgelshski. They connected with family and friends and it's possible they are now in an area without cell coverage. Reporter: As for Lucas fowler's father, a police chief inspector in Australia, he spoke for the families. It really is the worst ever love story, because we now have two young people who had everything ahead of them tragically murdered. Reporter: So sad and in that press conference police did seem concerned, George. They're not saying that there is a serial killer on the loose in Canada but as you mentioned, urging people to remain vigilant to stay only in established campgrounds and even to set up check-in types with their families. Yeah, they got to take precautions. Thanks very much.
This transcript has been automatically generated and may not be 100% accurate.