The committee’s investigators are zeroing in on events attended by members of domestic extremist movements like the Proud Boys and Oath Keepers in 2020.

Investigators for the House Jan. 6 committee are scrutinizing rallies and events as far back as a year before the Capitol riot in an effort to identify a broader network of planning and the causes of the attack, according to a half-dozen people helping conduct the committee’s investigation who spoke with NBC News.

The committee’s investigators are zeroing in on events attended by members of domestic extremist movements like the Proud Boys and Oath Keepers in 2020. Those events include Covid lockdown protests, counterprotests to some racial justice demonstrations, armed protest activity focused on state Capitols across the U.S., and “Stop the Steal” rallies that occurred prior to Jan. 6, 2021.

The goal, according to several of the investigators who spoke with NBC News, who requested anonymity to discuss the ongoing investigation, is to determine whether these earlier events were “proving grounds,” opportunities to network, or places to encourage one another to “cross red lines” into future violence.