Ricks was serving as the Special Agent in Charge for the FBI's Oklahoma City field office when, on April 19, 1995, Timothy McVeigh destroyed the Alfred P. Murrah Federal Building in downtown Oklahoma City, Oklahoma. It was the most significant act of terrorism on American soil until the September 11 attacks in 2001, claiming the lives of 168 victims and injuring more than 680. As the Special Agent in Charge, Ricks worked with Governor of Oklahoma Frank Keating and senior FBI and United States Department of Justice officials in the response to, and later investigation of, the attack.