Alt.True-Crime is one crazy freaking place to talk about crime stories. It’s been on the Internet forever. I’ve never checked how far back the messages go, but the Usenet in general has been around for 27 years or so, and you can search Google Groups back to 1981, though by the time you get that far back, the results begin to thin out considerably.
One thing I’ve realized in the last 4 years or so — a lot of people who started using the Web in the last 5-6 years don’t know the Usenet or the Google Groups even exist (they are not always one and the same). I’ve found some interesting stuff in Usenet discussion groups related to crime stories I’ve covered.
Beware, though — the Usenet in general is one of the most troll-friendly places on the entire Web. If you truly believe Internet is serious business, you don’t need to go there. I’d also recommend setting up a separate e-mail account entirely to post, if you do post there — spambots and hackers troll Usenet groups all the time, looking for fresh meat.
Still, alt.true-crime can be a great source of entertainment, dismay, and links to stories you’ve missed. It’s at least worth the read.