SEATTLE (AP) — Sixteen years after federal prosecutor Thomas Wales was shot to death in his Seattle home, Deputy Attorney General Rod Rosenstein said Wednesday the unsolved case remains a top priority of the Justice Department.

Rosenstein joined other federal and local law enforcement officials in a conference room named for Wales to plead for anyone with knowledge about the killing to come forward. Several big-name law firms and some of Wales' former colleagues said they were increasing the reward for information to $1.5 million.

"It is not acceptable for Tom's family, friends and colleagues to remain in a state of uncertainty about how he died," Rosenstein said. "It is not acceptable that his killer remains unpunished."

Wales, an 18-year veteran of the U.S. Attorney's Office in Seattle and president of the gun-control group Washington CeaseFire, was shot through a window as he worked in his basement the night of Oct. 11, 2001. The killing happened at a time when authorities were focused on the terrorist attacks of a month earlier.

Neighbors heard the gunshots and saw a man hustling to a parked car, but no one was ever arrested. Some shell casings were left behind, and while authorities determined the murder weapon to be a Makarov pistol outfitted with a replacement barrel, the gun itself apparently hasn't turned up.

Several times over the years authorities have pleaded for the public's help in solving the case, including on some anniversaries of the killing. They've taken out advertisements in gun-industry publications and released a sketch of a man with a chipped front tooth who was seen dragging a small, nylon suitcase through Wales' upscale neighborhood shortly before the shooting.

Jay Tabb, the special agent in charge of the FBI in Washington state, said the investigation remains active. He said a task force served almost 50 subpoenas in the past year. Investigators have several theories about the case, some of which they're "very fond of," but they can't solve the case without help, Tabb said.

The news conference was "aimed at individuals we think potentially know something about this," Tabb said. "People talk; people are not very good at keeping secrets. ... Just a little bit of information could change the outcome of the investigation."

The FBI has been offering a $1 million reward since early in the investigation, but on Wednesday, Mike McKay, president of the National Association of Former United States Attorneys Foundation, announced that several prominent law firms and individuals were offering an additional $525,000. That included $100,000 apiece from Williams & Connolly, DLA Piper and Perkins Coie.

Seattle Mayor Jenny Durkan, who served as Seattle U.S. attorney under former President Barack Obama and who knew Wales, pledged $10,000 toward the $50,000 donation of her former firm, Quinn Emanuel, McKay said.

A commercial airline pilot was once identified as possible suspect. The pilot had been involved in a business that sought to build civilian helicopters using military parts. Wales had prosecuted the company and the pilot for fraud; the company pleaded guilty, but Wales eventually dropped charges against the pilot.

He has always denied any involvement in the killing.

The case is the subject of a new podcast, "Somebody Somewhere," which questioned the FBI's commitment to finding a killer. Rosenstein, who was also in Seattle for a forensics conference Wednesday, said the series was unrelated to the timing of the news conference or the DOJ's decision to restate its commitment to the investigation.

Amy Wales, the slain prosecutor's daughter, said she had no doubt about the department's efforts and commended investigators for their service "at a time when the Justice Department and the FBI are constantly maligned for partisan or self-interested reasons."


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