THE PAIRING has always had an air of awkwardness: the mayor, Charlie Hales, who took office calling for a "culture change" within the Portland Police Bureau, and the police chief, Mike Reese, who'd briefly flirted with a run at the city's top job himself, and more importantly, was hand-picked by Hales' predecessor.

For a while, they made it work.

Hales needed Reese to finish important work that had started well before he took office: federally bargained reforms designed to answer accusations that Portland cops use excessive force against people with mental illness.

Reese had his own agenda. He wanted to take the bow once a judge finally approved those reforms. He had a new training center to celebrate—a white whale that had eluded his predecessors. And he had to hold on long enough to fatten his pension.

But like most marriages of convenience, this one had long suffered from what might be charitably described as a lack of intimacy.

And while Hales and Reese kept a brave face in public, saying nice things about one another, city hall sources had long since commented on the growing cracks between them.

Hales wasn't communicating like he used to, sources say. Reese, meanwhile, had done his job in changing the bureau's force policies. But there were other, private fights, over things like money. It didn't help that Reese presided over several personnel scandals involving high-ranking officers and seemed to resent city hall's willingness to pepper the bureau with budget cuts—a fight that boiled over after two commissioners, Nick Fish and Steve Novick, needed Hales' help to get the cops to cooperate in a study of the city's supervisory ratios.

Which is why it was hardly surprising when Hales and Reese held a press conference on Tuesday, October 7, and announced Reese would be moving on. They'd been talking about it since July, Hales said. The timing didn't just make sense—it also let both men save face with a graceful transition.

The city's police reforms had finally, as of August 29, been accepted by a federal judge. Reese, last month, got to take his last victory lap over the training center. And city hall is still months away from its annual budget fight, another bad time to change bureau bosses.

Ironically, Hales didn't look too far from Reese when naming his replacement, picking his longest-tenured assistant chief, Larry O'Dea. O'Dea's been an assistant so long he was put there by Reese's predecessor, Rosie Sizer—someone Hales has met with to talk police issues since taking office.

O'Dea, a Portland cop for 28 years, is something of a surprising choice—known as a thoughtful cop's cop and reputedly not so interested in the politicking that typically accompanies the chief's gig. His hiring came without a national search, which Hales said would have been a pointless "exercise" in this case—and, sources say, without consulting Hales' colleagues in city hall.

That's not to say O'Dea will be a bad choice for the community policing agenda Hales dreams about.

O'Dea—who's regularly sat with the city's Community and Police Relations Committee, a forum for sensitive topics like racial profiling—has made improving relations with the city's minority communities a major focus. He's also said he wants the bureau, and its largely white male command staff, to look more like the community it serves.

Tellingly, he invoked Ferguson, Missouri, in making his point. He said the bad blood there is about "way more than what happened that night," when police shot an unarmed black teenager. It's about a fraught relationship between cops and community members that he says he wants to keep mending here, too.

O'Dea's appointment might help clarify something else that's been troubling city hall. It's been almost two years since Hales arrived, declaring police reform one of his top priorities. But some observers inside and outside government find themselves wondering whether that's still true.

Hales could blame the tangled judicial process that slowed the pace of reforms. He could point to a police chief he inherited. Today, neither of those things are problems.

And that means Hales will have at least a few months, before the fever of the 2016 election sets in, to really show us what he can do.