As a firefighter, I’ve occasionally encountered a homeowner or occupant who wasn’t happy about our presence or activities. The most recent was a fellow who lost it when we prepared to vent the roof of his home, and acted to interfere by attempting to climb the ladder and stop the truckies. He was tackled, handcuffed, and removed from the fireground by the police.
There was another individual who was a maintenance man at an apartment complex who had the habit of resetting the alarm panel prior to our arrival, such that we couldn’t determine if there was one faulty head, one bad zone, etc. and cite the complex for repair by their alarm services vendor. We asked, and then ordered him to leave the panel alone when an alarm activation took place. On strike three, he was removed by the PD for interfering with the operation of a fire department.
The only “crime” which is of interest to me is that of arson, as I’m the one who has to establish the basic cause and origin of the incident. Depending on the size of the fire, and whether or not a fatality accompanied the fire incident, I may summon the local, county, and/or state fire marshal, all of whom have law enforcement powers above that which the law confers upon me as incident commander, particularly the state FM, who is a specially trained state trooper.
That said, if I see evidence of illegal activity not connected with my reason to be on the property, a courtesy advisory is given to the PD, and they can choose to handle it as they wish. Examples would be: a grow op (fire hazard via overloaded wiring), a meth cook (oom waiting for a b). Otherwise, we don’t go rooting around in your home or business playing Jr. detective.
While we enjoy a measure of protection from lawsuit, we’re still tasked with adherence to nationally recognized standards, typically those promulgated by the NFPA. If we, as a department, or I, as IC, fail to maintain the operation in accord with those standards, that immunity becomes tenuous.