Weapons shipped into Jordan by the Central Intelligence Agency and Saudi Arabia intended for Syrian rebels have been systematically stolen by Jordanian intelligence operatives and sold to arms merchants on the black market, according to American and Jordanian officials. Some of the stolen weapons were used in a shooting in November that killed two Americans and three others at a police training facility in Amman, F.B.I. officials believe after months of investigating the attack. The Jordanian officers who were part of the scheme reaped a windfall from the weapons sales. The training program, which in 2013 began directly arming the...