TORONTO — DNA collected from the scene of a 1988 murder has been used to create images of a suspect in the unsolved homicide, police in Ontario said Tuesday as they released the sketches they hoped would lead to a break in the case.
Ontario Provincial Police have been investigating the death of 80-year-old Thera Dieleman for the last three decades, issuing reward posters and news releases at various intervals over the years.
A lack of progress in the case encouraged the force to examine technological advances related to DNA, and resulted in police working with a company in Virgnia to develop digital images of what the killer may have looked like in 1988 and what he could look like today.
"We believe using existing DNA evidence in this innovative way will ignite memories to help us bring a resolution to Thera Dieleman's family and her community," OPP Det. Supt. Ken Leppert told reporters.
"We recognize that there is no way to bring her back, however, we continue to do our very best to find out what happened."
Dieleman was found beaten and strangled in her home in Blandford-Blenheim Township, Ont., on Sept. 16, 1988. Police believe the widow put up a fight, potentially causing injuries to her attacker.
The man suspected in the case was believed to have been driving a flatbed farm truck on the day of the murder, police said, but little other information on him was available.
In February 2007, as a result of advancements in the field of forensic analysis, a DNA profile was developed from evidence at the scene of the murder, Leppert said. Investigators have compared the DNA to persons of interest but have found no match so far, he said.
The force eventually decided to try the DNA "phenol technique," which allows the prediction of physical appearance and ancestry from unidentified DNA evidence.
The OPP said it turned to Parabon Nano Labs, a DNA technology company in the U.S., for help developing the images of the suspect.
"Individual predictions were made for the subject's ancestry, eye colour, hair colour, skin colour, flattening and face shape," said Leppert.
As it has been almost 30 years since the murder occurred, the sketches produced are scientific approximations and are not likely to be exact, he added.
"Environmental factors such as smoking, drinking and diet, and other non-environmental factors such as facial hair, hairstyle and scars cannot be predicted by DNA analysis," he said.
Police said they hoped the images will lead to new information from the public.
"The individual that killed Mrs. Dieleman has had 30 years of freedom," Leppert said. "Solving this mystery will also remove a dangerous offender from society before they harm someone else."
A $50,000 reward for information leading to the arrest of Dieleman's killer remains on offer.
Gabriele Roy, The Canadian Press