[ralph84]

Checks and balances are essential to the American way of government. Law enforcement should have to follow the Constitution, which means dealing with the check of obtaining a warrant. If the reason is really that compelling you’ll have no problem convincing a judge or magistrate.

[levinb]

I guess that's the point I was trying to make - in our case we were not conducting a criminal investigation. And if we were headed that way (which only happened every once in a while) then yes, we'd have to go in to Criminal Mode rather than Public Safety mode, and 4th and 5th Amendment obligations where back on.

[jkaplowitz]

Wouldn’t 5th amendment self-incrimination protections be in place even if the compelled questioning is purely part of a public safety investigation? Those protections are not about whether the particular kind of questioning is itself a criminal investigation but instead about whether the person is being compelled by the government to give answers that could tend to incriminate them.

For example, maybe your concern is just how fast and recklessly a boat was going with the goal of figuring out if they are a threat to fresh into another boat, but maybe the person doesn’t want to open themselves up for Boating Under the Influence or Controlled Substances Act criminal charges (whether or not they are legally guilty).

5th amendment self-incrimination protections apply even in compelled congressional testimony and routine tax return filing obligations, which are definitely not criminal investigations.

4th amendment protections also apply well beyond the criminal context, although I can well believe that your public safety investigations may have fallen into a judicially recognized exception. For a legally very clear example, no law can constitutionally authorize an LEO to nonconsensually conduct a warrantless suspicionless search of someone’s home to see if they might have failed to pay any applicable taxes or duties on any imported cigarettes which they may happen to have present there.

(Emphasis on suspicionless - the legal answer would probably be very different if the LEO sees someone transporting a pallet of imported cigarettes from the home into a truck in their driveway following having received a tip from the FedEx customs clearance people, even if there’s no time for a warrant. But there’s no constitutional reason for any investigation like this, whether about criminally intentional tax evasion or merely noncriminal accidental tax underpayment, to be occurring without suspicion.)