The bombs Shamsud-Din Jabbar built with the explosive known as RDX would have had devastating effects were it not for an amateurish blunder.

The attacker in the New Orleans vehicular attack used a rare explosive compound in two homemade bombs that failed to detonate, according to senior law enforcement officials. Investigators are examining how Shamsud-Din Jabbar learned about and produced a rare explosive never before used in U.

The FBI is also bracing for a leadership change expected to produce dramatic upheaval at the nation’s premier federal law enforcement agency.