Rigsby was pulling the strings on the high school renuion episode.
He did seem to find the next of kin information on Selby Vickers rather easily, and without being asked. Also knew about the airfield where Gabe Nyland came to town. And he said to Van Pelt he'd never been to Rancho Rosa before.
Also Gabe Nyland was running for Lieutenant Governer. We don't know if he won, but several episodes show the CBI going to work on cases at the request of the Lieutenant Governer. Most notably, the season 6 episode when Cooper and Haffner show up with a letter from the Lieutenant Governor stating that they will be kept informed on this case.