Sam: Well, in patrol work, you don't know from moment to moment who you are talking to or what their reaction is going to be to justify your presence. Let's say, for example, a patrol officer stops someone for a traffic violation. It seems as though that would be a very low-stress situation.
Interviewer: Yes, it is a very low-stress situation.
Sam: But the truth is, there are more police officers injured during a routine stop.
Interviewer: Really?
Sam: Really! That's why all police officers are taught from the very beginning to be aware of their surroundings. People back over policemen, people shoot policemen, people jump out at policemen --
请问People back over policemen, people shoot policemen, people jump out at policemen中的back over、jump out at是什么意思？

我个人的见解是“從后面偷襲”和“突然跳出來反抗”