Perhaps Walsh came close to catching Karr in another Cold Case. The letter is a taunt in many ways. Perhaps the part that says "Don't try to grow a brain, John" is really directed to Walsh? (Now that sounds a bit far fetched but a twisted mind does funny things.)
Where was Walsh from?
They were living in Florida when the crime happened.
http://www.cnn.com/2005/US/03/17/cnn25.tan.walsh/index.html
It looks like they're taking him to California first.
http://www.cnn.com/2006/LAW/08/19/ramsey.arrest/index.html
New York.
At least he was when his son was abducted and murdered.
I'm not sure where he was born but I can google.
I googled and found in Wikipedia that he was born in Auburn, New York (whereever Auburn NY is...).
My bad...he was indeed living in FL not NY when his son disappeared. But I am correct that he was originally from NY. But in the mind of someone who tries to make something out of the fact that a person has a southern heritage, the fact is FL is a southern state.