According to the Richland County Sheriff's Department, Dylann Roof's sister, Morgan, was arrested on Wednesday after a school administrator learned that she brought drugs, pepper spray and a knife to her South Carolina school.
She has been charged with marijuana possession and two counts of carrying weapons on school grounds.
A judge set her bond at $5,000 and she is not allowed to return to the school.
According to ABC News, investigators said Morgan also posted content on Snapchat that alarmed fellow students, but was not arrested for it.
Her brother, Dylann, was sentenced to death last January for shooting nine black church members during Bible study in a racially motivated attack at Emanuel AME Church in South Carolina in 2015.
He became the first person to face execution for federal hate crime convictions.
Stay up to date with the latest news stories from a Christian perspective. Sign up to our daily newsletter and receive more stories like this straight to your inbox every morning.