From Wikipedia, the free encyclopedia. Mike Doyle is an American actor, screenwriter, director and producer. He is best known for his recurring roles in the television series Law & Order: Special Victims Unit, playing Forensics Tech Ryan O'Halloran, and Oz, playing Adam Guenzel. It was on the set of Oz that Doyle met George Morfogen, whom he would cast in Shiner, a short film written, produced and directed by Doyle that debuted at the 2006 Tribeca Film Festival. Doyle also wrote and produc ...