Jay Tabb, of the FBI, fielded that question. “Another way to look at it is, people talk. People aren’t good at keeping secrets. Other people might have talked about it in those past seven years.” (Michael McKay said, “People may have heard something in a bar. They may have heard some pillow talk.”) [This was not from Mayor Durkan, as earlier noted. Thanks to Gene Johnson for the correction.] “Just that little bit of extra information might change the outcome of the investigation,” Tabb said. “The FBI’s easy to find. Please come forward.” Please talk with us had been the payoff line of all the speakers’ remarks.

As a matter strictly of law enforcement, there seemed two possible readings of this presentation. One is: Maybe they’re really close. For more than a decade, attention in Seattle has centered on one specific person, who was the focus of a grand-jury investigation, and whose home has been searched multiple times by authorities. He’s a commercial airline pilot, who was 40 at the time of the killing, and is 57 now, and had been involved in a fraud case that Wales was prosecuting. His circumstances and identity are so well known that, even though he’s not named in most news reports because he’s never been charged (Jeffrey Toobin’s is an exception), his lawyers are routinely quoted by name, and some of his past legal brushes are mentioned in the press. But he’s had alibis, as Toobin explains.

Does the press conference mean that the authorities are closing in? Do they have an idea that people who know something, and have stayed quiet this long, might be ready to flip—with the extra half-million dollars, and the renewed appeals to do the right thing? The Seattle Times reported on Wednesday that the FBI had found evidence “strongly suggesting” that the shooting “involved a conspiracy and a hired gunman,” citing an FBI official familiar with the investigation. If the case closes sometime soon, then in hindsight this may seem a move of Mueller-like prosecutorial strategic cunning.

And if not? Then the other theme of the press conference will be the one that justified the effort and fanfare of putting it on.

Every one of the speakers urged people who might know about the case to come forward, and every one of them said that this would be the “right” thing to do. But they all stressed something else as well: that doing justice in this case mattered even more than in “ordinary” killings, because a defense of law enforcers is a defense of the law itself.

“Any attack on a law-enforcement officer is an attack on our entire justice system,” Rosenstein said as he began the session. “It is an attack on the rule of law … We will continue to pursue this case for as long as it takes to achieve justice.”

Amy Wales, who spoke last, visibly bore the burden of her family’s grief. But, she said, “this case has always been about more than one man. My father’s murder was an attack on the institutions of the United States.” If a man like him “can be brutally murdered for carrying out his prosecutorial duties,” she said, then “the law-enforcement and judicial processes that keep all of us safe are fundamentally compromised.”