UPDATE Oct. 29, 2019:

Patrick Leon Nicholas, 55, was charged with first-degree murder in the killing of 16-year-old Sarah Yarborough on Dec. 14, 1991. Her body was found raped and strangled in a wooded area of the Federal Way High School campus. Nicholas has pleaded not guilty, the Federal Way Mirror reports.

MORE: Covington man pleads not guilty in 1991 murder of Federal Way girl - Federal Way Mirror

March 19, 2018:

In Washington state, new DNA evidence may finally lead investigators to one the state's most wanted killers.

Sarah Yarborough, 16, left her home early one December morning in 1991 to go to practice with her high school dance team. She was never seen alive again. Her body was found just feet away from a busy high school. Even with so many potential witnesses, the killer's identity remains a mystery haunting cops for decades.

Now, nearly 30 years later, will new findings put heat on this ice-cold case?

She was the all-American girl next door, a wholesome teenager with long red curls. Sarah Yarborough had everything in front of her. Her brother Andrew Yarborough remembers Sarah was always there when he needed her. But those good times with Sarah ended in a harrowing way.

Andrew remembers he was just 11 years old and playing in a Saturday morning soccer tournament when police came to the game to speak to his parents.

Something was terribly wrong. That morning, around 8 a.m., Sarah pulled up to Federal Way High School to meet her cheerleading team. The girls were about to leave for a competition, but Sarah never made it on the bus. She was strangled.

In a shocking discovery, around the same time the cheerleaders were loading the bus, two boys found Sarah's body lying just 150 feet away from her parked car in a brushy area near the high school.

"We didn't have anybody that heard any screaming, but we did have a jogger that saw our suspect interacting with Sarah's body in the bushes," said retired King County Sheriff's Detective Jim Allen.

Strangled and reportedly sexually assaulted, Sarah was left for dead in broad daylight.

Sarah's brother Andrew tells Crime Watch Daily that she did not have any enemies, wasn't involved in drugs or with a bad crowd, and didn't have any scorned ex-boyfriends.

The violent and random murder gripped the quiet community of Federal Way, Washington with fear.

"It changes things," said King County Sheriff's Captain Ted Boe. "Afterwards, I think people were much more conscious about being in groups, not being alone."

Ted Boe would know about those changes firsthand: that's because he went to high school with Sarah Yarborough all those years ago.

"I did. I knew who she was. You would see her in the hallway and she was on the drill team. Can't miss the red hair," said Capt. Boe.

And in an ironic twist, Boe is now the sheriff's captain heading up the team in charge of solving the crime.

"This is the case that would be the most important for me as I look at the wall. And not to discount the other cases, but this one I have a personal tie to," said Capt. Boe. "It means something to me to be able to say that while I was here, we solved this case."

Following Sarah's murder, there was a massive manhunt. More than 2,500 tips poured in, and most importantly, invaluable physical evidence was collected from the crime scene.

"We had a full male profile from the scene," said retired detective Jim Allen. "There's been several samples submitted over the years, but no matches."

Over the years there have been only a few persons of interest identified, but no arrests were ever made.

What stood out to these individuals about the person leaving the bush?

"There was an age range of probably, maybe like a late teenager, early 20s," said Allen. "They thought he had kind of shaggy, dirty blond hair. Now we know there's a high likelihood he has blue eyes."

With that description, forensic artists drew a composite of the killer. But even with that sketch, the mystery man's identity eluded cops.

"It just seemed like a very solvable case from the beginning. And it had a lot of media exposure, a lot of community interest," said Jim Allen.

After thousands of hours of investigation, much to the frustration of detectives, the case froze over.

Any reason to believe the suspect is still living in Washington state?

"There's theories that the suspect could have been passing through, visiting the area. The suspect could be dead," said Allen. "Logic would cause you to believe that if you did this offense that you would end up in a felon databank somewhere. Yet we've had no matches over all these years."

But detectives never gave up hope, even scouring an ancestry database going all the way back to the birth of America in hopes of finding a match to that DNA.

"There was a direct relationship to 'Fullers' that came over on the Mayflower, which generated some tips. We looked at some local people with the last name that we eliminated through DNA," said Allen.

When you realized this do you think, "Wow, this is the big break in the case?"

"Yeah at the time we thought it was a huge break, but once again we were able to obtain DNA from everybody, and they were all eliminated," said Allen.

But could all those dead ends finally lead somewhere? Now, nearly three decades later, that rough sketch has been replaced with a new age-progression portrait. The technology is called "polymorphism" and uses DNA markers from the suspected killer to envision what he would look like now.

You have DNA recovered at the scene. You have reliable peers, eyewitnesses. You have the age progression. You have a lot to go on, and yet still nothing. That much be incredibly frustrating.

"It is frustrating," said Boe. "It's all there. If we can identify the suspect, this is a solvable case. We don't need a confession to solve it. We have everything as there to get us to the finish line."

But that finish line now requires the help of someone who might recognize this killer.

And perhaps nobody would be happier to see an arrest in this case than Sarah's brother Andrew, who has a strong message for the man who took his sister's young life so long ago.

"Take responsibility for your actions. It's as simple as that," said Andrew Yarborough. "It's time. It's been a long time."

If you have any information related to the Sarah Yarborough case, you're asked to contact the King County Sheriff's Office at (206) 296-3311, email tips to MCUtips@kingcounty.gov, or you can submit a tip anonymously to Crime Watch Daily.