Police in the city of South Milwaukee said Misty Cook was arrested Sunday for the offense of being in possession of a firearm as a felon.
She will be referred to the Milwaukee County district attorney’s office for charges, the police said.
The arrest came after Wade Michael Page opened fire on worshippers attending a service in nearby Oak Creek, Wisconsin, killing six.
“The cause of this arrest is not connected to the shootings in Oak Creek and has no connection to this investigation,” FBI Special Agent Teresa Carlson told reporters at a news conference.
She said the FBI accompanied by Milwaukee police interviewed Cook at her home Sunday night, at which time they noticed a weapon and subsequently arrested her.
Carlson described Cook as “cooperative” but did not immediately provide more details.
A racist former soldier with links to white supremacists, Page seems to have drifted from job to job since leaving the army in 1998 and had become a singer in a so-called “white power” band.
The FBI, which did not have an active file on Page before the killings, has said he is the subject of a “domestic terrorism” probe and that his ties to white supremacist groups are being scrutinized.
Page apparently died of a self-inflicted gunshot wound to his head rather than from police fire, the FBI added today.