The Forensic Teacher Magazine looks like a pretty informative site for mystery/crime writers. You can subscribe free, read online articles, or purchase copies. They are also looking for teachers or writers to share their forensic experiences and lesson plans. They have a list of topics for articles and the pay is 2cents a word. Just click on the guidelines link at the top of the page. There was a mini-mystery on the site but I didn't see any guidelines for submitting one of those.
Hat tip to writingcareer.com