Cold Case Solved With Confession, But Killer May Still Go Free

June 7, 2010— -- For the last 20-years Karen Hull has been haunted by nightmares of what happened to her missing son.

Now that three men have confessed to throwing the 16-year-old boy off a bridge, Hull is angry that only one of the three allegedly involved in the murder faces the possibility of a few years in jail.

Hull, 59, is also furious the case took so long to be solved, furious that police admittedly assumed her son, Walter Ackerson Jr., was just another runaway and didn't follow up on leads.

"I think the most shocking thing was ... the story that I had been told by a girl back in 1990," Hull told ABC News. "She said she had heard there had been a fight, and my son had been thrown off a bridge. The police never investigated that, they never talked to anyone about it."

Now the detective who is responsible for cracking the case agrees with Hull's assessment.

"I certainly can understand. This was bad police work, unfortunately," Sgt. Mark Meister of the Lincoln County Sheriff's Department told ABC News.

"Some work was done, but at that time they wrote a report saying this was nothing more than another runaway and that ended it. I'm not saying it would change the outcome, but more should have been done," said Meister.

"Karen has every right to be angry and frustrated with what happened, I totally sympathize with her," Meister said.

Meister stumbled onto the Ackerson case and his prodding eventually provoked one of the boy's alleged killers to confess.

But now Hull faces the possibility that, even with a confession, her son's murderers may go free.

Hull said she and Walter tried to start a new life in Puyallup, Wash., after she says she escaped an abusive relationship. According to Hull, her son was suddenly thrust into a much larger school district, and experienced problems with other classmates.

"He was small, and he was struggling with the other kids picking on him. A lot of bullying that back then, just wasn't addressed like it is today," she said.

Walter didn't want to go to school and Hull thought they found an alternative in the Oregon Job Corps.

"It appeared to be a really great opportunity. He thought he was going to be able to get his education and move on and do something with it," she said.

Walter moved 200 miles away to the Angell Federal Job Corps Center on the Oregon coast. She said for two weeks her son kept in regular contact with her and his grandmother, but that suddenly stopped. The last time they heard from Walter, Hull says, he told his grandmother Delores "this place is nothing like you think it is."

On April 5, 1990 Hull said she received a call from an administrator at the Job Corps and learned Walter had been missing since March 24.

"They told me my son ran away to Wyoming with another boy, and I asked them to file a missing person's report and they asked me why? I said because he is 16," Hull said.

Two weeks later, Hull said she found out her son was never reported missing, so she drove the center to speak to a director and the last three students who were allegedly with her son.