A man serving a life sentence for kidnapping and other crimes while in a Georgia prison built two bombs which he mailed to a District of Columbia office building and the federal courthouse and building in Anchorage, Alaska, prosecutors allege.

The accused bomb maker, 55-year-old David Cassady, allegedly put the two explosive devices into the mail at his prison in Tattnall County on Jan. 24, 2020, according to an indictment issued by a grand jury in U.S. District Court in Statesboro, Georgia.

The bomb that went to Washington, D.C., was mailed to the Bond Building, whose office tenants include the Department of Justice.

The indictment alleges Cassady made and sent the bombs with the intent to “to maliciously damage or destroy, by means of fire or explosive, a building in whole or in part owned or possessed by, or leased to, the United States,” and “created substantial risk of injury to a person.”

Neither bomb exploded.

Cassady is charged with one count of making an unregistered destructive device, two counts of mailing a destructive device and two counts of attempted malicious use of an explosive.

“Protecting our personnel and facilities is a fundamental role of our office and of our law enforcement partners,” said U.S. Attorney Jill Steinberg, whose office is prosecuting Cassady. “We also will take action against inmates who seek to commit crimes and harm the public from behind bars.”

Barry Paschal, a spokesman for the U.S. Attorney’s Office, declined to comment when asked to explain the more than four-year lag between Cassady allegedly mailing the bombs, and being charged in the case.

Paschal said he could not comment on details of the case beyond those contained in the indictment.

That charging document did not say how Cassady allegedly made the bombs while locked up in prison, the size of those devices, how he mailed them from prison, and why he chose the DOJ headquarters and the federal courthouse and building in Anchorage as his targets.

A spokeswoman for the Georgia Department of Corrections said, “Cassady was able to manipulate primarily items he was authorized to possess into makeshift explosive devices.”

“We appreciate the support of our federal partners in ensuring that justice will be served on this individual for his role in jeopardizing the safe operations of our facilities, and most importantly, the safety of the public,” said the spokeswoman, Joan Heath.

Cassady has a long criminal record dating to the late 1980s, when he was sentenced to prison for three years after convictions for six counts of first-degree forgery.

Corrections Department records show he began serving his most recent stint in prison in 1993, after being convicted of kidnapping, aggravated sodomy, impersonating an officer and false imprisonment.

While in prison in Tattnal County, Cassady was convicted of crimes in 2019 including terroristic threats and acts, false statements, gang participation, and conspiracy, records show.