Sad, neither of those works on Android. Pressing the power button activates the emergency call screen with a countdown to call emergency services, and power + volume either just takes a screenshot or enables vibrations/haptics depending on which volume button you press.

Oh wow, just going into the "should I shutdown" menu also goes into pre-boot lock state? I didn't know that.

my understanding is that they can hold you for a couple days without charges for your insubordination but as a citizen they have to let you back into the country or officially arrest you, try to get an actual warrant, etc.

If you are a US citizen, you legally cannot be denied re-entry into the country for any reason, including not unlocking your phone. They can make it really annoying and detain you for a while, though.

[dead]

This is the third person advocating button squeezing, as a reminder: IF a gun is on you the jig is up, you can be shot for resisting or reaching for a potential weapon. Wireless detonators do exist, don't f around please.

Is that actually true? I'm fairly confident my work Mac requires a password if it's idle more than a few days (typically over the weekend).

Settings -> lock screen -> “Require password after screen saver begins or display is turned off”

Shift+Option+Command+Q is your fastest route there, but unsaved work will block.