Federal authorities arrested two individuals for conspiring to attack Baltimore power grids, officials said in a press conference on Monday.

Officials said that Brandon Russell and Sarah Clendaniel “took steps” to shoot at numerous Baltimore electrical substations, aiming to “completely destroy this whole city.” Officials said that the two of them were taken into custody last week before they could carry out their plans.

“The accused were not just talking but taking steps to fulfill their threats and further their extremist goals. Russell provided instructions and location information. He described attacking the power transformers as the greatest thing somebody can do. In her own words, Clendaniel said she was determined to do this,” the FBI special agent in charge said at the press conference.

Russell and Clendaniel met while incarcerated, and Russell was released from prison in 2021, according to The Washington Post.

Their arrests come months after an individual shot at two electrical substations in Charlotte, N.C., causing roughly 40,000 people in the area to lose power. The FBI is also investigating that attack.

According to the Southern Poverty Law Center, Russell is the founder of neo-Nazi group the Atomwaffen Division. The Atomwaffen Division was founded in 2016 and holds extremist neo-Nazi views, including supporting the idea of lone wolf violence, according to the Anti-Defamation League.

Officials said at the press conference that the individuals’ “extremist views” may have motivated their plans to attack the grid.

Russell was sentenced to prison for five years in 2018 for the possession of an “unregistered destructive device and for unlawful storage of explosive material,” according to the Department of Justice. When officials discovered the explosive material, Russell was living with Devon Arthurs, another member of Atomwaffen Division, who was arrested for allegedly shooting and killing two other members of the group at the time, according to the Department of Justice.