Foretelling a larger view of the prosecution, US attorneys on Friday charged the leaders of four regional Proud Boys cells with conspiracy for planning and coordinating the domestic terrorist attack on the US Capitol January 6th, Politico reports.

Prosecutors unsealed charges against Ethan Nordean of Seattle, Zach Rehl of Philadelphia, Charles Donahoe of North Carolina and Joseph Biggs of Florida alleging that the four orchestrated the attack on the Capitol with the intent of overwhelming the police on scene and breaching the building.

While these are not the first conspiracy charges filed in relation to the coup attempt–prosecutors filed similar charges against ten low-level members of the Oath Keepers weeks ago–these charges are the first against leaders of one of the groups suspected of working to undermine the election at the behest of Donald Trump.

The indictment contains information that the four became scared after Proud Boys president Enrique Tarrio was arrested days before the January 6th attack and attempted to delete discussion threads they had on messaging apps in an apparent attempt to cover their tracks.  They then set up other messaging threads using different services and pseudonyms.

Using an unspecified encrypted app, they also set up two channels, “Boots on the Ground” and “New MOSD,” for the Proud Boys who were participating in the January 6th attack.  Approximately sixty people joined the two channels.

They discussed a new chain of command in Tarrio’s absence, with Nordean (who goes by the alias Rufio Panman) deemed to be in charge of the January 6th activities.

“Rufio is in charge, cops are the primary threat,” the unindicted co-conspirator told associates on the encrypted channel, per the indictment. “[D]on’t get caught by them or BLM, don’t get drunk until off the street.”

The channels detail plans in which some of the leaders would go to the Capitol first, while other Proud Boys would follow in small groups.  Once there, they would gather in larger groups to proceed with the attack.

It is unclear how law enforcement got access to the encrypted messages.  They may have infiltrated the group before or they have an informant who turned the information over to them.