INDIANAPOLIS, Indiana - A former FBI agent from Indiana who helped investigate the 9/11 terrorist attacks and the Oklahoma City bombing in 1995 has been charged with possessing and distributing child pornography. 

Donald Sachtleben, 54, of Carmel, Indiana is accused of trading pornographic images and videos of children from his home computer, said U.S. Attorney Joseph Hogsett for the Southern District of Indiana in a news release. 

Acting on a tip, FBI and Indiana State Police investigators obtained a warrant and searched Sachtleben's hard drive, Hogsett said. 

Sachtleben was a visiting assistant professor in Stillwater with the Department of Forensic Sciences at Oklahoma State University in the fall of 2011 and spring of 2012.   

"The mission of our Project Safe Childhood initiative is to investigate and prosecute anyone found to be engaged in the sexual exploitation of children," Hogsett said   

Sachtleben could face up to 20 years in prison for the distribution charge and up to 10 years for the possession charge.  Both charges also carry up to a $250,000.  

Sachtleben is in federal custody and scheduled for a hearing Thursday in Indianapolis.