increase font size Founding member of Oath Keepers first to plead guilty in Jan. 6 Capitol riot Prosecutors hope Jon Ryan Schaffer’s plea spurs others to provide additional evidence in hopes of avoiding long prison sentences. By Spencer S. Hsu and Devlin BarrettWashington Post Share WASHINGTON – A founding member of the Oath Keepers arrested in the Jan. 6 riot at the Capitol pleaded guilty Friday and agreed to cooperate against others in the case – the first defendant to publicly flip in the sprawling domestic terrorism investigation that has led to charges against more than 410 people. The plea comes exactly 100 days after Jon Ryan Schaffer and hundreds of other supporters of former president Donald Trump stormed the Capitol, allegedly in an effort to prevent Joe Biden from being confirmed as the next president. Prosecutors hope Schaffer’s plea spurs others to provide additional evidence in hopes of avoiding long prison sentences.