how do you know for a FACT that the person is not a threat, you don't. the person just broke into a residence WITH people in it, you have no idea what their intentions are. they could be sitting at the dining room table watching sponge bob in a onsie and that doesn't mean they are not a threat to you.
the charges wouldn't stem from the arriving officers they will come from the detectives and the prosecutors office. the arriving officers could be fine with it, but who knows what if anything the detectives/prosecutors could/would charge you with