An Alabama man was arrested and indicted this week on charges that he detonated an explosive device outside the Alabama attorney general’s office in late February, the U.S. Justice Department announced Wednesday.

Kyle Benjamin Douglas Calvert, 26, of Irondale, was charged with malicious use of an explosive and possession of an unregistered destructive device, the Justice Department said.

The explosion outside Attorney General Steve Marshall’s office occurred around 3:42 a.m. on Feb. 24. No injuries or major damage were reported.

“That device had the characteristics of an IED, and Calvert added a substantial number of nails and other shrapnel to increase its destructive capability,” a U.S. attorney’s office wrote in detention memo filed Wednesday, using the initialism for an improvised explosive device.

The memo alleges that law enforcement officers found that the suspect also placed stickers on state buildings “advocating for various political ideologies” the night of the explosion, including stickers promoting antifa, anti-police and anti-Immigration and Customs Enforcement sentiments.

Calvert has expressed his “belief that violence should be directed against the government, and he has described his inability to control his own violent, aggressive impulses,” the memo added.

Court documents revealed a monthslong investigation involving the use of video surveillance to track the suspect’s whereabouts the night of the crime, matching the suspect vehicle to license plate reader information, social media, an analysis of the suspect’s gait and mannerisms and analysis of the explosive device.

The detonation happened one day after the state attorney general’s office said Marshall did not plan to prosecute in vitro fertilization providers or families after a controversial Alabama Supreme Court ruling. The motive authorities attribute to the suspect has not been released.

“My staff and I are breathing a collective sigh of relief this morning knowing that this individual has been taken off the streets,” Marshall said in a statement Wednesday. “Although more information will be provided in the weeks to come, I think it is safe to say that this was not a random act of violence. We are grateful to our federal and local partners for their assistance in this matter and are pleased that the offender faces federal charges carrying significant prison time.”

If he is convicted, Calvert could face up to 20 years in prison with a mandatory minimum of five years behind bars, the Justice Department said. One of the charges carries a maximum of 20 years in prison, while another has a maximum of 10 years in prison, but the sentences could run concurrently, the Justice Department said.

A Justice Department representative said Calvert was appointed a federal defender. The attorney could not immediately be reached for comment.

U.S. Attorney General Merrick Garland thanked the FBI and law enforcement partners, adding in a statement, “The Justice Department has no tolerance for acts of violence targeting those who serve the public.”

Public officials are facing threats at the state and federal levels. Last year, U.S. Capitol Police investigated 8,008 threat assessment cases, about 500 more than in the previous year.

Below the federal level, about 43% of state legislators and 18% of local officeholders have experienced threats, according to a report by the Brennan Center for Justice, a left-leaning think tank that analyzes topics including voting rights, elections and gerrymandering. The survey, published in January, found 38% of state legislators reported that the amount of abuse they are experiencing has increased since they first took office, compared to 16% who said it has decreased.