If you have ever wondered about the forensic uses of Photoshop, here is a great place to learn about it.
Forensic Photoshop Blog
The blog is written by Jim Hoerricks. Jim is a Photoshop Instructor, an Author, and a court qualified expert witness in Forensic Video Analysis who also happens to work for a law enforcement agency in one of the US' major metropolitan areas.
Check it out, it is worth reading.