An assistant U.S. attorney and active gun violence opponent was shot at his Queen Anne home late last night and died early this morning in what is being described as an execution by those close to the investigation.

Federal investigators and Seattle police are trying to determine a motive for the death of Tom Wales, 49, but several sources said the case has all the markings of a deliberate hit.

Wales was working at a computer in the basement of his home shortly after 10:30 last night when a gunman apparently went up to a basement window at the back of the house and fired at least five shots.

Two of those shots hit Wales, one in the neck and the other in his side. He was taken to Harborview Medical Center in Seattle where he died at 1:17 a.m. today, according to the hospital.

A senior federal law enforcement official said the incident does not appear to be random and based on what investigators know now, Wales was a target and the shooting was "no doubt deliberate."

Wales' office in the U.S. Attorney's Office has been sealed as part of a criminal investigation in case his work as a prosecutor plays into his death, sources said. Wales' cases also are being reviewed.

Wales, who also was board president of Washington CeaseFire, a group working to end gun violence, worked in the U.S. attorney's fraud investigation unit.

His former wife, Elizabeth Wales, is a former Seattle School Board member.

"It appears to be a hit right now," one federal source said today. "It has the hallmarks of a hit. But to go farther than that, to get into why he was killed, would be speculation at this point."

Harold Malkin, a former assistant U.S. Attorney who replaced Wales as first assistant to former U.S. Attorney Kate Pflaumer, said Wales prosecuted fraud and white-collar crime and was "completely committed and dedicated to that office.

"This is a terrible loss. And the cruelest irony of it all is that he was killed with a handgun," Malkin said, noting that Wales, as president of Washington CeaseFire, was on what Malkin said was the "right side of one of the big issues of our times — gun control."

The FBI, the federal Bureau of Alcohol Tobacco and Firearms, ATF and Seattle police are investigating the shooting.

Neighbor Dan Olsby, 27, said that when he heard gunshots at the Wales' home, in the 100 block of Hayes Street, he first thought they were firecrackers.

"I didn't even flinch to get up out of my chair," Olsby said later, as he stood with his father, Don Olsby, on the sidewalk at First Avenue North and Hayes Street last night.

Homicide detectives and Seattle Police Chief Gil Kerlikowske arrived at the house within an hour of the shooting. FBI agents arrived around 12:30 a.m.

"We don't have any suspects, but it's now a joint investigation with the FBI because federal charges may apply," Seattle police spokesman Duane Fish said last night.

Bruce Carter, a former assistant U.S attorney who retired this year, was stunned by the death. "What a tragedy. He was my good friend. I'd go down the hall and we'd talk things over," Carter said. "For someone who dedicated his life to fighting violence, I'm just stunned."

"I am just flabbergasted," said Harry McCarthy, another former assistant U.S. attorney, who worked for more than a decade with Wales.

"He'd been there such a long time and was such a great guy," said McCarthy. "It just boggles me."

Seattle Mayor Paul Schell today expressed great sadness about the shooting death of Tom Wales, a prominent neighborhood and gun-control activist and former federal prosecutor.

Forrmer assistant U.S. attorney Malkin said Wales was a "terrific fellow" who loved to run and was recently on the upswing from some difficult personal problems. Seattle Mayor Paul Schell said in a prepared statement that Wales cared passionately about Seattle and his death is a great loss to our community.

Schell knew Wales through his work with Washington CeaseFire as well as the Seattle Planning Commission. Wales served on the commission from 1995 through 2000 and was chairman from 1999-2000.

"I encourage citizens to honor Tom's life by making contributions in his name to Washington CeaseFire," Schell said. "We must stop senseless gun violence."

Wales, a federal prosecutor for nearly two decades, was a graduate of Harvard College and Hofstra University School of Law.

Wales has served with the Federal Bar Association board and with the Washington State and King County Bar Associations.

Wales has two grown children, a son and daughter.