Pentagon

A source told CBS News that the man detained in the discovery of a suspicious vehicle outside the Pentagon Friday morning has been identified as a lance corporal in the U.S. Marine Corps Reserve. Lance Cpl. Yonathan Melaku told authorities during questioning Friday morning that he was carrying explosive materials, the source told CBS News investigative producer Pat Milton.

Former FBI Special Agent Brenda Heck, who heads the office of its anti-terrorism division of the Washington field office, told reporters that no explosive material was found in a backpack, the suspect took the time he was arrested. Ammonium nitrate is a chemical compound commonly used in fertilizers and explosives are used in the right concentration.

A law enforcement official spoke on condition, anonymity said officials found what appeared to be an unknown quantity of ammonium nitrate. The official, who was not entitled to the information, said nothing was found that would have allowed the explosion. The official said tests done in the matter and determine the exact concentration.