At a press conference this morning Mayor Mike McGinn announced that interim police chief John Diaz was his choice to lead the department. Diaz has been in limbo since last May, when then-chief Gil Kerlikowske was tapped to be Obama’s Drug Czar. Although there was some controversy during his tenure, Diaz’s appointment really shouldn’t be a surprise.As SeattleCrime points out, Diaz and McGinn made a number of public appearances together over the last month. Which is not something you do when you’re thinking about picking the other guy.That other guy was Ron Davis, the chief of relatively tiny East Palo Alto, California. The police union didn’t like the idea of a guy who had commanded a force of only 40 officers making the leap to a city that has over 1,300. And the city council didn’t seem happy with either, privately asking McGinn to re-open the search.Something to watch in the future: how Diaz handles negative press. He’s got a habit of saying the wrong thing at the wrong time, and the way he chose to deal (or, more accurately, not deal) with two recent incidents — the “Mexican piss” face-stomp and video of a cop punching a teenage girl — indicates he’s got a lot to learn about what it means to be the public face of a department.