If the code was real it would have been solved by someone.
I suspect he just made up nonsense to make them waste time. There was a movie on a couple of days ago which was pretty bad. They tried to say it was likely some guy but they really had very little to go on.
Handwriting analysis is not nearly as accurate as most believe.
It reminded me of a very long TV movie about Ted Bundy. It spent several days following a bunch of detectives in Seattle who basically had little to do with his capture or conviction.
He was caught by a cop in Pensacola, Florida after murdering a little girl plus the Chi Omega attack. He was actually executed for the murder of the little girl.
Either that or, since it is the History Channel, the killer will be revealed as an ancient bigfoot astronaut.