At the same time convicted serial killer Robert Pickton was prowling Vancouver's downtown eastside for victims, another man was doing the same.

While Pickton brought sex trade workers in his truck to his Coquitlam farm, this other killer dumped women's bodies up logging roads in the Fraser Valley.

And while Pickton sits in a federal prison, this other killer roams free.

Police say it's time he was caught.

"We will absolutely not give up," said Staff Sergeant John Cater of the E Division Missing Women Task Force. "These women did not deserve to meet the demise in the way they did."

The bodies of Victoria Younker, Tammy Lee Pipe, and Tracy Olajide were all found in mountains near Mission in the Fraser Valley in 1995. At the time, police noticed similarities in the cases and believed they had a serial killer on their hands.

"I think when I saw the second crime scene, that was the indication that something was going on," said Sgt. Paul McCarl, who was the file manager in the early days and now works for RCMP Unsolved Homicide.

"As time progressed, another month and a half, the third victim was found in Mission in similar terrain, and the scenes were basically the same," he said.

Police thought they had found the culprit when they raided Pickton's farm in 2002. They found the DNA of more than 30 women, but they found no trace of Olajide, Pipe, or Younker.

Younker's family thought they would get answers then -- but were crushed when they found out Pickton wasn't connected to their cases.

"It really hurt," said Younker's sister Cathy. "I want the public to know that it wasn't Pickton and there is another serial killer out there."

She says her sister worked as a stripper in Victoria and had a loving relationship. But then health problems and drugs caused her to gain weight.

"She started working on the streets here in Victoria," said Cathy. "She could make more money to support her habit in Vancouver, so that's where she went."

No one knows whose vehicle Younker got into, but she got into the wrong one. Cathy never saw her sister again.

16 years later, police are still hunting Vancouver's other serial killer. They look for any patterns to connect victims with suspects. Last month they asked RCMP members in Alberta to interview someone.

They already have perhaps what would be a key piece of evidence: the killer's DNA.

"Every week someone else is being compared that we're interested in, and being eliminated," said McCarl. "Eventually we'll hit on the right person, and that person will be identified."

But to narrow down the suspect list police need to solve certain mysteries. They want to know exactly what a set of tiny yellow flecks that were found in the crime scene are.

They want to know who had a red four by four that could have navigated the rough terrain in the Valley. McCarl says a fleck of red automotive paint is connected to the killer.

They also showed a set of zap straps that are like one the killer would have used.

On top of that, the team of detectives constantly goes over the patterns of interactions that the victims and the suspects may have had to find new leads.

"Each of us thinks about the case pretty much every day," said Cater.

Police and the families are asking for help from the public -- any tip could be useful and should be forwarded to the tip line: 1-877-687-3377.

Cathy Younker says she wants to find out what happened to her sister.

"I'm hoping to get this man off the streets," she said. "My sister's gone, no matter what happens. But I'm hoping that people can, if they have any tips, if they see anything different, call in and let the police know."

It's been 16 years, but Younker's family still hope they can one day learn the truth.

With a report from CTV British Columbia's Jon Woodward