The first criminal charges in special counsel Robert Mueller’s Trump-Russia probe are secret for now — but that doesn’t necessarily tell us much on its own.

Because the indictments are sealed, we don’t yet know who is being charged or what they are being charged with.

Ken White, a libertarian-leaning lawyer and former assistant US attorney who tweets and blogs as “Popehat,” walked through a brief explainer on Saturday morning, after the news that the first criminal charges in Mueller’s investigation of possible Russian government collusion with the Trump presidential campaign had been approved by a federal grand jury.

The takeaway was: Sealing charges is pretty routine. It prevents the target of an indictment from knowing they’re about to be charged and arrested, which limits the risk of defendants destroying evidence or any shenanigans when they are eventually brought in.

A mini-lawsplainer about sealed federal indictments: /1 — Popehat (@Popehat) October 28, 2017

When a federal grand jury approves ("returns") an indictment, it's presented to a magistrate judge. /2 — Popehat (@Popehat) October 28, 2017

Under normal circumstances it would then be filed as a new criminal case and become part of the public record, soon on PACER /3 — Popehat (@Popehat) October 28, 2017

But Federal Rule of Criminal Procedure 6(e)(4) lets a magistrate judge seal the indictment https://t.co/jNmRcYHGak /4 — Popehat (@Popehat) October 28, 2017

That simply maintains its secrecy and prevents it from being public on PACER or otherwise. /5 — Popehat (@Popehat) October 28, 2017

Sealing indictments is routine in federal criminal law. You do it so defendants don't know they've been charged and will be arrested.../6 — Popehat (@Popehat) October 28, 2017

..for reasons including (in theory) preventing them from fleeing or destroying evidence, allowing you to arrange search warrants, /7 — Popehat (@Popehat) October 28, 2017

...and allowing you to arrange to arrest them without violence or a circus. /8 — Popehat (@Popehat) October 28, 2017

Generally the indictment is unsealed after they are arrested and make their first appearance in federal court. /9 — Popehat (@Popehat) October 28, 2017

It's not an unusual or remarkable procedure in federal criminal law and doesn't reliably signify anything about the case. /end — Popehat (@Popehat) October 28, 2017

So for the time being, we wait. CNN reported that arrests could be made as soon as Monday.