The murder of Terry Dolan, a retired Seattle policeman mowed down in cold blood 30 years ago, might finally get solved.

After retiring from being a motorcycle cop, Dolan thought owning a gas station in Everett would be a good way to make a living. On February 2, 1981, someone shot him to death during a robbery.

In an exclusive interview with Team 7 Investigators, Dolan's widow tells us detectives have long suspected her husband's killer was someone he knew. Confidential police sources tell KIRO she is right. Detectives now suspect another former Seattle police officer of killing Dolan.

PART 1: Former SPD Cop Suspected Hit Man

PART 2: FBI Delay Makes Widow's 'Blood Boil'

PART 3: Possible Hit Man Cop Named In '81 Murder Of Retired Officer

PART 4: FBI Backlog Could Have Cost Kirkland Doctor His Life

PART 5: DNA Match Made Too Late Because Of Feet-Dragging By Feds

PDF: Police Confirm DNA Match in Realtor Murder: See Proof Here

SLIDESHOW: Suspect, Murder Victims, Crime Scenes

TIMELINE: Slow Road To DNA Match

It's been three decades since Terry Dolan died fighting off an attacker inside his gas station along Evergreen Way. His widow, who asked that we shield her identity, says Terry was counting the till money from a long holiday weekend. A neighbor heard a loud bang - then squealing tires - as a metallic blue-green colored car drove away from the gas station at 90 mph.

Dolan’s widow, Joan, remembers that day all too well.

“When he left that morning, something told me something was wrong. I had this feeling. I got a call from Hal, Terry's old partner, and he said, ‘Did you know there was trouble at the station this morning?’ I said, ‘No,’ and then I just asked him, ‘Was Terry killed?’- and he said ‘Yes.’”

The headlines in the newspaper screamed "Retired officer found shot to death" and "Rewards offered in slaying of ex-police officer."

But according to Terry Dolan's widow, Everett detectives didn't consider the murder much of a mystery. They immediately had a prime suspect: Terry's friend from his days as a Seattle police officer another former cop named Gary Krueger. Krueger was someone Mrs. Dolan never liked.

She described her feelings to Team 7 Investigators.

“He had the eyes of a timber wolf. These cold, blue eyes and they're vacant. At the time, I told Terry, ‘I don't know who this man is. I don't know how you know him, but he's evil.’”

For reasons never made clear to Mrs. Dolan, Kreuger was never charged with the gas station robbery or murder. The case languished for years. Then in September of 2010, she received two calls, one from a detective in Seattle and another from the Everett Police Department. They both saidTerry’s killer had finally met his justice. Prime suspect, Gary Krueger was dead.

Those calls coincide with the discovery of Krueger's waterlogged body floating in Lake Washington.

Joan says, “Someone from the Seattle department recognized him when they went to the lake the first time. They knew it was Krueger, so they were following him for years. Oh, they knew. They knew it had to be him.”

Sources from a variety of police agencies tell KIRO Team 7 Investigators Krueger is suspected of killing not only Dolan in 1981, but Bellevue attorney Jim Barry in 1984, and realtor Mike Emert in 2001. Nobody has ever been charged with these crimes.

What's the connection? Nobody knows yet for sure, but police documents, uncovered by Team 7 Investigators, show Krueger had a long history of severe gambling debts. We've spoken with associates of Krueger who have been told by detectives that Kreuger may have been paying off some of those debts by killing people for someone out of state.

The Everett police department isn't saying much about the Dolan murder except that it’s an active, ongoing case. Terry Dolan's widow doesn't expect Gary Kruger will ever get charged, since he's already dead, but she says she will sleep a little easier knowing he's no longer a danger to anyone.