Feel a bit sorry for the sherif yes he should have gone in but none of us know if we would. It's really easy to say you would have been gun out running towards danger but until you are faced with that reality you'll never know.
he doesn't necessarily have to turn into Rambo here
simply entering the building, firing at the suspect and/or just shouting at him/making him aware of the presence of police could well be sufficient... it at the very least gives the suspect something else to be concerned about and restricts his movement/potentially allowing kids to escape... it doesn't mean the police officer at say one end of a corridor/hall or whatever needs to break cover and go charging at the suspect sacrificing his own life in the process etc..