Astoria is indeed in Oregon. Her Charley Project page says she jumped from the Glenn L. Jackson Memorial Bridge, which spans the Columbia between Vancouver, WA & Portland, OR.
The location of Michael's vehicle is interesting. Capitol Hill is, among other things, the longstanding locus of gay culture in Seattle. Since time immemorial there has been a cluster of gay-friendly businesses along Pike between Broadway and 14th. It's possible his vehicle was found in north...
I don't mean to make light of Matthew's disappearance or judge his lifestyle but as one whose birth date is only three weeks earlier than Matthew's in 1984 just about every kid selling weed on any given street corner was wearing pretty much this exact outfit. Given that Oregon has a long and...
I'm probably not telling anyone anything they don't already know, but the 'circle A' symbol is the 'anarchy symbol,' frequently seen on kids in the punk rock scene (as well as actual anarchists). Here's an Imgur image of just such a tattoo.