Forensic analysis quickly determined that the disk had been used by the Christ Lutheran Church in Wichita, as well as a reference to the name "Dennis." An internet search determined that "Dennis Rader" was the president of the church council. He was arrested on February 25. Oh and he was a cop at the moment.
Edit: #1 arrest date February 25 2005
Edit #2 He was an Animal Control officer (or something along those lines), but was not a police officer.