A 30-year-old cold case involving the double homicide of a young Saanich couple could move a step closer to being solved when Washington state authorities hold a news conference Wednesday.

The killings of Tanya van Cuylenborg, 18, and Jay Cook, 20, have stumped investigators for years, but the Snohomish Country Sheriff's office says it has "new suspect information from snapshot DNA phenotyping" that will be released.

The high school sweethearts were reported missing Nov. 20, 1987, after taking the ferry from Victoria to Port Angeles, Wash. on what was supposed to be an overnight trip to Seattle.

Four days later, van Cuylenborg's body was discovered in a ditch 20 kilometres south of Bellingham. According to police, she had been raped and shot in the head.

Cook's body was discovered under a bridge in Monroe, Wash., two days after that. He had been beaten and strangled.

New DNA technique

Snapshot DNA phenotyping is a relatively new technique that involves using DNA to predict the physical appearance and ancestry of a suspect or unknown person.

"We've used it in over 150 cases and with 100 different agencies both in the U.S. and internationally," said Ellen McRae Greytak of Parabon Technologies, the company behind Snapshot DNA.

"We've helped solve quite a number of cases, [some] as old as 25 years."



DNA from the suspect was collected when van Cuylenborg's body was found, however authorities have never been able to trace it to anyone.

Jay Cook's body was found under this bridge in Monroe, Wash. He had been beaten and strangled to death. (CBC archives)

The murders of van Cuylenborg and Cook have been in and out of the news through the years with a number of attempts to drum up new tips.

Two years ago, an anonymous donor offered a $25,000 reward in exchange for information that would help solve the case.

In 2010, a team of FBI criminal profilers and British homicide experts worked on the case without any luck, while in 2008 the couple's picture was featured on playing cards distributed to inmates at Snohomish County jails.

In 2000, Snohomish County detectives said they believe the couple may have been killed by serial killer Robert Yates of Spokane, Wash., although he was later ruled out.

The van that Cook and van Cuylenborg were driving was found abandoned near the Bellingham Greyhound station. (CBC archives)

That same year, Yates was sentenced to 408 years in prison after confessing to the murder of 13 women. All of his victims had been shot in the head.

Van Cuylenborg's wallet and keys were discovered behind a Bellingham tavern while the brown van the couple had been driving was located near the Bellingham Greyhound station.

At the time of the murders, van Cuylenborg's father said it was possible the couple had picked up a hitchhiker.

Families of the two victims are expected to attend the news conference.

With files from CBC Radio's On the Island