SAN FRANCISCO (CBS SF) — Four members of a militia group identifying with the extremist “boogaloo” movement have been charged with obstructing the investigation into the murder of a federal officer last year in Oakland.

A federal grand jury indicted Jessie Alexander Rush, Robert Jesus Blancas, Simon Sage Ybarra, and Kenny Matthew Miksch, all members of the California Grizzly Scouts, a militia group based in Northern California.

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The four were charged with conspiring to obstruct justice by destroying communications and other records related to the May 29, 2020 shooting death of Federal Protective Service officer David Patrick Underwood at the Oakland federal building. The indictment also charges Rush with an additional count of obstruction of official proceedings and Blancas with an additional count of destruction of records in official proceedings.

The indictment was filed March 23 and unsealed on Friday, announced Acting U.S. Attorney for the Northern District of California Stephanie Hinds and FBI Special Agent in Charge Craig Fair.

.According to the complaint, members of the Grizzly Scouts, including Rush, 29 of Turlock; Blancas, 33, a transient Bay Area resident; Ybarra, 23, of Los Gatos; and Miksh, 21 of San Lorenzo, communicated with each other on WhatsApp referencing the boogaloo movement and the killing of police officers and other law enforcement. The term “boogaloo” refers to a politically motivated civil war or uprising against the government.

Boogaloo militia-linked suspect Steven Carrillo is charged in Underwood’s murder and the attempted murder of another officer working with Underwood. He is also charged with the murder of Santa Cruz County Sheriff’s Sgt. Damon Gutzwiller and attempted murder of other deputies in an ambush on June 6, 2020 in the mountain community of Ben Lomond.

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The complaint alleges that on the day of Gutzwiller’s killing, a member of the Grizzly Scouts exchanged messages on the WhatsApp group with other Grizzly Scouts, in which that member allegedly told the group that he was preparing to engage in a shoot-out with law enforcement. The member allegedly asked the other Grizzly Scouts to come to his aid.

The indictment alleges Rush immediately instructed the Grizzly Scout member to delete evidence on his phone. Less than an hour after the shooting in Ben Lomond, Blancas also allegedly deleted files related to the Grizzly Scouts from a Dropbox account.

Within hours of the shooting, members of the Grizzly Scouts including Rush, Blancas, Ybarra, and Miksch allegedly began to reconnect on an alternative communications application, and the four defendants each deleted records of the WhatsApp group communications from their phones, including previous discussions about targeting law enforcement, the complaint alleged.

Ybarra made his initial court appearance on Thursday while Rush and Miksch were scheduled to appear in federal court in San Francisco on Friday.

Blancas was scheduled to make his initial appearance on April 12. Blancas is also facing separate federal charges of enticing a minor to engage in sexual activity.

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If convicted, the defendants each face a maximum statutory penalty of up to 20 years in prison and a fine of $250,000 for each of the conspiracy, obstruction, and destruction charges.