In this Jan. 6, 2021, file photo insurrectionists loyal to President Donald Trump breach the Capitol in Washington. Prosecutors secured the first guilty plea in the major case brought against members of the Oath Keepers extremist group in the attack on the U.S. Capitol, while an Indiana woman who became first person to be sentenced for the Jan. 6 riot avoided time behind bars.

An Indiana woman on Wednesday became the first defendant to be sentenced in the Jan. 6 insurrection at the U.S. Capitol and avoided time behind bars, while a member of the Oath Keepers extremist group pleaded guilty in a conspiracy case and agreed to cooperate with prosecutors in a major step forward for the massive investigation.

The two developments signal that the cases against those charged in the deadly siege are slowly advancing, even as the U.S. Department of Justice and the courthouse in Washington, D.C., struggle under the weight of roughly 500 federal arrests across the U.S.

Graydon Young, who was accused alongside 15 other members and associates of the Oath Keepers of conspiring to block the congressional certification of Joe Biden’s presidential victory, pleaded guilty to two counts: conspiracy and obstruction of an official proceeding. It was the first guilty plea in the major conspiracy case brought against members of the group.

The second charge calls for up to 20 years in prison, but U.S. District Judge Amit Mehta said federal sentencing guidelines call for Young to serve between 5 1/4 years and 6 1/2 years behind bars.