Tacoma police released composites of suspects in two 30-year-old murders of girls as part of an exercise by a group of experts.

On Wednesday, Tacoma police mobilized their child abduction response team, or CART, in an effort to generate new evidence and information in hopes of finding someone who may have seen something the day the girls vanished, but never came forward.

The composites were generated by DNA phenotyping, which identifies genetic markers that provide basic characteristics. The composites are approximate and are are much like a witness giving a description (DNA) and a computer program making a sketch based on known appearance factors.

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Kidnapping experts are treating the cold cases as if they just happened in an attempt to solve the murders.

The results of the exercise could be life-changing for the families of the victims, who were raped and murdered in Tacoma four months apart in 1986, 13-year-old Jennifer Bastian and 12-year-old Michella Welch.

Welch was found in Puget Park on Wednesday, March 26. Bastian was found at Point Defiance Park on Monday, August 4.

No arrests were ever made and police had always thought that one man was responsible, but authorities say new evidence shows they were not killed by the same person.

”The crime scenes were very similar. The girls were of similar age in a very similar geographic location, so we operated on those facts,” Loretta Cool with Tacoma police told reporter Kevin McCarty last week.

The plan is to use the new specially trained and nationally certified team in abduction to help solve the cases by re-introducing them to the public.

The experts are meeting for two days at the Pierce County Emergency Management Headquarters. About 75 people from the Tacoma Police Department, FBI, Pierce County Department of Emergency Management and South Sound 911 will participate in the exercise.

Authorities say the man responsible for the murder of Jennifer Bastian has a fair skin complexion, green or blue eyes with blond or red hair.  The suspect has Northern European ancestry.

The man responsible for the murder of Michella Welch has a fair skin complexion, brown or hazel eyes with blond or brown hair. The suspect has Northern European and Native American ancestry.

"It's 30 years removed now, and we're hoping that is someone had that feeling or that thought that now they will come forward and give us that information," Cool said last week.  "Somebody saw something and didn't call. Somebody knew something and felt like maybe we already knew it and didn't call."

The two girls would have been 42 and 43 years old today.

Investigators say it's possible the killers are still alive.