A bit of calculating based on Revelation and the number of the beast--if CBI Ron's real name is Ronald John--he comes out as 666
He is the only person I've found of the possibilities who adds up this way
Course his last name might not be John but it very well could be--and it's a fair bet Ron is actually Ronald
A bit of a stab in the dark--but 666 may have been the clue at the end of episode one
Personally-I'd always been suspicious of Lisbon and Van Pelt--but this makes me think it could very well be Ron (along with info pulled from other theorys that suspect him that I'm not going to plagiarize!)
Course I could be wrong--but the name does count up to 666