Good, 37, was shot dead in her car by the ICE officer on January 7.
Homeland Security Investigations and FBI “agents executed an arrest in Minnesota”, US Attorney General Pam Bondi wrote on X.
“So far, we have arrested Nekima Levy Armstrong, who allegedly played a key role in organising the coordinated attack on Cities Church in St Paul, Minnesota. We will share more updates as they become available. Listen loud and clear: WE DO NOT TOLERATE ATTACKS ON PLACES OF WORSHIP.”
She later wrote that officers had also arrested Allen for the action where an immigration official was apparently leading a service, according to US media.
“WE WILL PROTECT OUR HOUSES OF WORSHIP,” she posted.
FBI Director Kash Patel posted on X that Armstrong had been arrested under the FACE Act, a law intended to protect those seeking to access abortion clinics and places of worship.
Minnesota has sought a temporary restraining order for the ICE operation in the state which, if granted by a federal judge, would pause the sweeps. There will be a hearing on the application next week.
There have been confrontations between federal agents and protesters who have demanded a full investigation of Good’s killing, with officers frequently deploying pepper spray and tear gas.
A number of school children have walked out of classes in protest at the ICE operation in the city.
The officer who fired the shots that killed Good, Jonathan Ross, has neither been suspended nor charged with any crime. Trump and his officials quickly defended his actions as being legitimately made in self-defence.
The federal immigration sweeps in Minneapolis occurred amid a highly politicised fraud investigation in Minnesota.
- Agence France-Presse