ARAPAHOE COUNTY, Colo. (CBS4)– The anonymous tipster credited with cracking an Arapahoe County cold case that languished for nearly two decades is explaining why he remained in the shadows for so long, how he came to believe his roommate had committed murder and why he finally guided police investigators to the suspected killer.

Robert Wilson (credit: CBS)

“It was making me crazy,” said Robert Wilson, the tipster, in an exclusive interview with CBS4. “It was killing me one way or the other.”

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In 1999, Wilson was living in the Copper Terrace Apartments in Arapahoe County, 6500 South Dayton Street, with a man with a similar name, Robert Williams.

Williams was known to have sexually harassed several women in the apartment complex and had been convicted in 1983 in California of manslaughter, for strangling an ex-girlfriend. Williams did several years in prison on the manslaughter charge before being released.

Rebecca Bartee, 41, a new prosecutor for the Arapahoe County District Attorney, moved into the apartment adjacent to the one Williams and Wilson were living in just one month before her death.

(credit: CBS)

Wilson said late one night when he was coming home, he spotted a figure peeping in an apartment window.

“I stood there for 5 minutes. Lo and behold it was Robert looking in the window at 2:30 in the morning,” said Wilson.

There had been other reports of Williams bothering women at the complex.

Wilson told CBS4 that when he came home for lunch one day, he found Williams with his hands on Bartee.

“He had his hands on her and I swung on him. He fell and hit the concrete.”

Then, when Bartee failed to report for work June 7, 1999, her body was found in her bathtub. She had been strangled.

Wilson said he came home for lunch that day, before Bartee’s body had been discovered. He said he noticed Bartee’s door was open in the middle of the day which he found to be odd.

He said as he ate lunch in his apartment while watching TV, Robert Williams walked into the apartment.

“He was acting just strange as could be. He walked in slow and when he saw me he stopped. He just looked at me and this was a look I’ve seen in different instances. I already knew what the story was. He did something.”

(credit: CBS)

Wilson said Williams walked silently to the bathroom and stayed there for an unusually long amount of time.

“I knew something happened. I knew he screwed up.”

But Wilson said he had to go back to work and when he returned home that evening, there was police tape on Bartee’s door.

He said, “I knew right away,” that Williams had murdered Bartee.

John Kellner, the current Arapahoe County District Attorney, ran his office’s cold case unit. He told CBS4 that Arapahoe County detectives immediately focused on Bartee’s ex-husband and showed little interest in the two single men who lived next door to her, one of which, Williams, had a criminal history of violence against women.

“That’s how many of these cases become cold,” observed Kellner.

He said detectives were so focused on their initial theory, they simply didn’t spend much time looking at the two men who lived next door to Bartee.
Wilson confirmed that detectives spent very little time investigating him or Robert Williams.

“They should have come,” said Wilson. “I should have been a prime suspect from the get-go.”

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According to an affidavit in the case, police investigators asked Robert Williams to provide a DNA sample but he refused. Investigators then moved on.

Asked why he didn’t say more to police at the time, Wilson explained, “It wasn’t the way I was brought up.”

He said from an early age, he had relatives who spent time in prison and he was taught, “You don’t tell on people close to you, close to your family. You just don’t do that.”

Leads in the case soon dried up and Kellner said, “The case was pretty much shelved.”

It remained unsolved for years.

But Robert Wilson had a change of heart. He explained to CBS4 he had been through some health scares and what he witnessed, and what he suspected in 1999, had been gnawing at him for years.

Robert Williams (credit: CBS)

“It started building up over the years in a way I couldn’t control it anymore. I started thinking, if I’m going to go out, I have to get this out of me. It started making me angrier and angrier until I was about to pop.”

In 2017, Wilson made contact with Arapahoe County Sheriff’s Office investigators and told them what he knew about Robert Williams, and what he observed and experienced in 1999.

Investigators then began taking a closer look at Williams. When they did, they found out about his manslaughter case in California. They learned of his history of sexually harassing women at his apartment complex.

“These are things we wish law enforcement had found, uncovered in 1999. It probably would have led to Robert Williams being arrested then and being held accountable,” noted Kellner.

Now, with Wilson’s firsthand account in 2017, investigators put Williams under surveillance. As they secretly watched Williams, they got a sample of his DNA from a water bottle he threw into a trash can. They found his DNA matched a hair found in Rebecca Bartee’s bathtub.

In August 2017, the Arapahoe County Sheriff’s Office announced that due to “new evidence” they had arrested Robert Lee Williams for investigation of first-degree murder. He was immediately jailed.

“The informant’s information made this case,” said Kellner. “So without that information, it would have stayed where it was: absolutely cold.”

Wilson said he feels guilty about waiting so long to share his observations.

“It made me crazy,” he recalled. “I feel kind of responsible, to be honest with you, that it ever happened because I was too slow in the beginning and I was too slow afterward. So I have a lot of blame for myself. I should have said something, I should have done something.”

He said he is hopeful that revealing himself and telling his story will help him find peace and bring solace to the family of Rebecca Bartee.

“I hope she’s able to rest and her parents and her family can rest,” he said.

Kellner said he understands how Wilson carried guilt for years but said, “Rebecca’s family carried that burden in a much deeper way and he brought closure to them. That is really redemption for him.”

Kellner said Wilson’s story is a reminder that it is never too late for people with information about a crime to contact law enforcement and share what they know.

“So if anyone knows something,” said Kellner, “Bring it forward, let us help somebody’s family get justice.”

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Robert Williams died in jail in 2018 before he could face trial in the Bartee murder. He was 71 years old at the time of his death.

Brian Maass