Following a raid on the Branch Davidian church by the Bureau of Alcohol, Tobacco and Firearms on February 28, 1993, the FBI assumed command of the Waco Siege.
[5] At the direction of newly appointed United States Attorney General Janet Reno, FBI agents mounted a final assault on the Davidian church on April 19.
By the end of the day, 76 Branch Davidians were dead, including women and children, and federal agents had seized control over the compound.
Ricks' negligence in handling the Waco siege led to reforms in training procedures for FBI agents.
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.
Concurrently with his service as Secretary, Keating also appointed him Commissioner of Public Safety, giving Ricks direct control over the Oklahoma Highway Patrol.