Kyle Benjamin Douglas Calvert, 26, of Irondale, Alabama, pleaded guilty in federal court to aggravated use of an explosive device, according to a Friday press release from the Department of Justice.

Calvert admitted to detonating a bomb fragment outside the Attorney General's office in downtown Montgomery, Alabama, on February 24, 2024. press release.

Calvert constructed the bomb himself using nails, screws and an accelerant to maximize the impact of the explosion, and before the attack he had plastered several state buildings with stickers bearing various political messages, including some in support of Antifa, the paper reported. Court DocumentsHowever, Calvert denies any ties to Antifa. (Related: Antifa woman convicted of rioting: reports)

The stickers included phrases such as “Support your local Antifa” and “Anti-fascism is community self-defense.”

“The defendant used nails and screws as shrapnel to create a bomb and detonated it outside the Alabama Attorney General's office, endangering the public and the local community,” Attorney General Merrick B. Garland said, adding that “public servants should not be targeted for simply performing their duties.”

Kyle Benjamin Douglas Calvert of Irondale, Alabama, pleaded guilty in federal court to building and detonating a bomb outside the Alabama Attorney General's office. Calvert admitted to building the bomb and using nails and screws as shrapnel.https://t.co/eves1Iq96L

— Melissa (@Proudmimi12) August 24, 2024

FBI Director Christopher Wray echoed Garland's sentiments, saying, “Violence and destruction of property will never be tolerated. The FBI and our partners will continue to work together to hold accountable those who seek to harm or intimidate our communities.”

Calvert's sentencing has not yet been scheduled. He faces a minimum of five years and a maximum of 20 years in prison. The case continues to be investigated by the FBI with assistance from the ATF.