Who shot Tim Brenton?

That's the $105,000 question right now in Seattle. A little after 10pm on Halloween night, Brenton -- a Seattle cop -- was shot to death while working his beat with a trainee. Chief Detective Jim Pugel described the murder as an assassination; they seem to think the killer staked out his victim and planned the murder fairly well.

If I may play Armchair Sherlock for a moment, here's a glimpse at the psych profile the cops have released:

[Investigators] say [the killer's] skills with weapons suggests some prior training, such as previous employment or hobbies involving firearms. The gunman may have practiced for the shooting...

It's probable that the gunman had been outspoken about a deep personal grievance, perhaps involving his employment or position in life. And even though he shot a police officer, he may admire or act like them, investigators said.

This says to me that Seattle investigators believe they're looking for a sociopath who will probably kill again. In other words, they're thinking this is the work of a person who could become a serial killer.

[Statistically, serial killers] are [...] fascinated with the police and authority in general. They have either attempted to become police themselves but were rejected, worked as security guards, or served in the military. Many, including John Gacy, the Hillside Stranglers, and Ted Bundy, have disguised themselves as law enforcement officials to gain access to their victims.

In a serial murder, the killer is usually unconnected to the victim; the murder asserts the killer's power over the victim; the murder is not done for profit; and the victim often has some kind of symbolic value for the killer. Oh, and, of course, there's gotta be three or four deaths, with a "cooling off" period in between.

I have no idea what's really going on, but it seems likely from the Seattle PD profile that they're looking for someone that they think will strike again in the coming weeks.