The US has charged Hamas leader Yahya Sinwar and several other prominent figures in the Palestinian group in connection with its deadly attack in Israel on 7 October last year.
The justice department said it was indicting six Hamas members with seven charges, including the murder of US citizens, conspiracy to finance terrorism and use of weapons of mass destruction.
The criminal complaint covers decades of alleged attacks by Hamas, as well as the unprecedented assault on southern Israel nearly a year ago.
It is the first step by US law enforcement to hold accountable the ringleaders of the 7 October attack, though up to three of those named in the indictment are dead and Sinwar is believed to be hiding in tunnels somewhere under Gaza.
In a video statement on Tuesday, Mr Garland said the defendants were responsible for “financing and directing a decades-long campaign to murder American citizens and endanger the security of the United States”.
The group also “led Hamas’s efforts to destroy the state of Israel and murder civilians in support of that aim”.
He noted the 7 October attack on Israel by Hamas, in which the group “murdered entire families” in “the deadliest massacre of Jews since the Holocaust”.
“They murdered the elderly and they murdered young children. They weaponised sexual violence against women, including rape and genital mutilation.”
He added that during the attack the group “murdered over 1,200 people” and “perpetrated the deadliest massacre of Jews since the Holocaust”.
Other Hamas leaders charged include former leader Ismail Haniyeh; Marwan Issa, the deputy leader of the organisation’s armed wing; Khaled Mashaal, who leads the group outside Gaza and the West Bank; along with Mohammed Deif and Ali Baraka.
The charges include conspiracy to bomb a place of public use resulting in death, conspiracy to finance terrorism and material support for acts of terrorism resulting in death.
The justice department’s complaint notes that all the “defendants are either deceased or remain at large”.
Haniyeh, Issa and Deif have all been reported killed in the past few months in attacks that were either claimed by or attributed to Israel.
The attorney general referred in Tuesday’s remarks to the killing last week of US-Israeli hostage Hersh Goldberg-Polin, 23, in addition to 42 other American citizens killed in the 7 October attack and 10 taken hostage.
“We are investigating Hersh’s murder, and each and every one of Hamas’ brutal murders of Americans, as an act of terrorism,” Mr Garland said.
If convicted, the group faces a maximum penalty of life in prison or a death sentence.
The charges were filed in February, but were kept under wraps until Tuesday in case the US had the opportunity to arrest any of the accused, an unnamed justice department official told CBS News, the BBC’s US partner.
Over the weekend, President Joe Biden condemned the Hamas killing of Goldberg-Polin, calling it “as tragic as it is reprehensible”.
“Make no mistake, Hamas leaders will pay for these crimes,” Mr Biden said.
Meanwhile, the UK has defended its decision to ban some weapons sales to Israel over concerns about how they might be used in Gaza.
Hamas attacked southern Israel on 7 October, killing about 1,200 people and taking another 251 hostage.
More than 40,000 people have been killed in Gaza since then in Israel’s ongoing military campaign, according to the territory’s Hamas-run health ministry.