A Seattle prosecutor was murdered decades ago and the reward was just increased to $2.5 million. Can you help?

Can you help?

The reward for information about the murder of Seattle federal prosecutor Thomas Wales has been increased from $1.5 million to $2.5 million as investigators plead for help to solve the 20-year-old case.

Around 10:40 p.m. on Oct. 11, 2001, Wales was killed in his home in Seattle, Washington.

The shooter stood in the backyard of Wales’ home and shot him several times through the basement window as he sat at his desk typing on his computer, according to the FBI.

A lone male suspect was reportedly seen fleeing the scene.

Wales died in the hospital the next day.

Wales worked for the Western District of Washington as an Assistant United States Attorney for more than 18 years, prosecuting white-collar crime cases on behalf of the United States.

Investigators have worked the case for 20 years but have made no arrests. A pilot from Bellevue, Washington, was identified as a potential suspect in the murder, but he has never been charged, according to King 5.

Investigators believe the killing was a hit job in revenge over a fraud case Wales prosecuted against the pilot, King 5 reported.

Agents have zeroed in on a small group of people from Snohomish County who they believe are connected to the killing, according to King 5.

On Oct. 11, U.S. Attorney Nick Brown announced a new set of investigators have taken over the case, King 5 reported.

"This means fresh eyes -- local prosecutors looking at the evidence in this case anew -- and working on strategies with the existing team to bring justice to the Wales family and our community," he said, according to King 5.

Seattle FBI Special Agent in Charge Don Voiret said the case is personal to investigators.

"The fact this hasn't been solved is personal to us," Voiret said, according to K5. "We want to bring closure to the family. For the people out there that might have information, turn that around. What if it was your family member, your father, your husband? You would want the case solved, too."

People can submit tips through walestips@fbi.gov or (800) CALL-FBI.