How to use "authorities" in a sentence

"Have the authorities ever figured out exactly why it happened?" Elliot asked.

"How did the authorities identify the body?"

In the course of preparing the exhumation request for the authorities, I discovered that my client's reaction was typical

That's what both the authorities and the mortician had told her

If the body were exhumed and reexamined by a top-notch pathologist, we'd almost certainly find proof that the cause of death wasn't what the authorities originally said it was."