There is the grey area: A noise heard downstairs--was it just something falling over? Do we all get out of bed and lose sleep and wait together? How long? If the situation is likely nothing, then I will carefully check it out (because I won't be able to sleep until I do, anyway). But if I know there are intruders in my house, I ain't gonna clear it myself.
Last week in the 5 AM darkness I noticed two SUVs stopped in the middle of our cul-de-sac. (This is very unusual.) Our streetlight casts a lot of glare and hard shadows, so it was tough to see what they were doing. I watched several guys opening their doors & hatchbacks and donning some sort of gear. Others were wandering aimlessly around the street near their SUVs, perhaps checking out the real estate bargains. When one of them hoisted on a vest and an equipment belt, my brain said "weapons" and I called 911.
When the patrol car rolled up, I could see (in the headlights) that the backs of the vests said "Federal Marshals". It turned out that they were setting a security perimeter around the last known location of a murder suspect. It didn't look like any security perimeter I'd ever seen in any military, U.S. or international.
They did not look like the good guys. They were in civilian clothes with unmarked SUVs, and they milled around in the cul-de-sac instead of ringing doorbells to talk to the neighborhood residents. They were way too casual in their behavior to look like law enforcement, and they didn't even know I was watching them from my front lanai. If they'd come on to our property then someone would've been hurt.
I thanked the patrol officer and then asked the Marshals what they wanted. When they explained the situation I invited them to check our yard (which overlooks the gulch they thought the suspect was hiding in) but they declined and said they'd been told the suspect had moved on. (They were trying to move on as well, but they were using jumper cables on one of their SUVs.) Two hours later everyone was back (augmented by a helicopter) and they arrested the suspect right where he'd been previously reported.
We have nothing in our home worth protecting, and I'm much more comfortable at the thought of scampering off like a scared bunny (carrying a cell phone). It turns out that my spouse prefers to fort up in our "panic room" with that cell phone while waiting on the police. I won't abandon her, but I'm very uncomfortable about being stuck in one place waiting for someone else to show up... instead of potentially spraining an ankle sneaking through the neighbor's yard in the dark.
A week later I'm still debating whether to e-mail the local police about the poor behavior of the Federal Marshals. My spouse suggests I should move on and avoid attracting attention to myself. My nuke attitude has trouble abandoning an opportunity for constructive feedback which may enable corrective training to avoid future problems.
Third Ala Moana shooting suspect captured after manhunt - Hawaii News Now - KGMB and KHNL
Hopefully word will get around the local criminal underground that my house should be avoided. 
