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.S. or European terrorist incidents. The homemade bombs placed in coolers by Jabbar failed to detonate, and authorities are investigating whether the failure was due to malfunction, lack of activation, or another issue. A transmitter and two guns recovered from Jabbar's truck are being sent to an FBI laboratory for testing.