Oakland Police Chief Howard Jordan told CNN that former nursing student One Goh, 43, walked into the building that houses Oikos University on Monday morning carrying a handgun, took a receptionist hostage and went hunting for a female school official that he believed had wronged him. One witness said Goh told students, “Get in line and I’m going to kill you all.” “They thought he was joking at first,” Paul Singh, whose sister Devinder Kaur, 19, was shot in the arm during the rampage, told Reuters. Goh then left, reloaded, and then fired more shots into a second classroom where some students were hiding before fleeing in one of his victim’s cars. “This was a calculated, cold-blooded execution in the classroom,” Jordan told CNN. “We don’t think the victims had any opportunity to resist, any opportunity to surrender,” he added.