DOJ charges senior Hamas leaders over involvement in Americans' deaths during Oct. 7 attack on Israel

The Justice Department unsealed charges Tuesday targeting multiple senior members of Hamas' leadership for their alleged involvement in the kidnapping and murdering of Americans during the terror group's Oct. 7 attack on Israel.

The criminal complaint, unsealed in the Southern District of New York, names six members of Hamas' leadership structure and details extensively their alleged terrorist activities on behalf of the group.

The complaint details seven criminal charges against the Hamas leaders including conspiracy to provide material support to a foreign terrorist group resulting in death, conspiracy to provide material support for acts of terrorism resulting in death, conspiracy to murder U.S. nationals, conspiracy to bomb a place of public use resulting in death, conspiracy to use weapons of mass destruction resulting in death and conspiracy to violate the International Emergency Economic Powers Act.

Among those named in the criminal complaint are Ismail Haniyeh, the Hamas leader assassinated in Iran in July, and Yahya Sinwar, who has been described by Secretary of State Antony Blinken as the "primary decider" in cease-fire negotiations.

The other defendants listed are Mohammad Al-Masri, Marwan Issa, Khaled Meshaal and Ali Baraka.

The charges were filed in February and kept under seal because the DOJ was hoping to be able to take Haniyeh and other members of the alleged conspiracy into U.S. custody, a DOJ official told ABC News, who added that it was no longer necessary to do so since three of the six charged are now deceased and given the recent developments in the region.

The charges accuse the group of financing and directing a "decades-long campaign to murder American citizens and endanger the security of the United States," Attorney General Merrick Garland said in a statement announcing the complaint's unsealing.

"As outlined in our complaint, those defendants -- armed with weapons, political support and funding from the Government of Iran, and support from Hizballah [Hezbollah] -- have led Hamas' efforts to destroy the State of Israel and murder civilians in support of that aim," Garland said. "In its attacks over the past three decades, Hamas has murdered or injured thousands of civilians, including dozens of American citizens."

Garland further confirmed in a statement Tuesday that the Justice Department is actively investigating Hamas' murder of six hostages over the weekend, including dual American Israeli citizen Hersh Goldberg-Polin.

"The charges unsealed today are just one part of our effort to target every aspect of Hamas' operations. These actions will not be our last," Garland said. "The Justice Department has a long memory. We will pursue the terrorists responsible for murdering Americans -- and those who illegally provide them with material support -- for the rest of their lives."

Hamas carried out an unprecedented incursion from Gaza into southern Israel by air, land and sea on Oct. 7, 2023, killing more than 1,200 people and taking 253 others hostage, according to Israeli authorities. Officials say there are now 97 hostages remaining in Gaza. Before the killing of the six hostages over the weekend, U.S. and Israeli officials had assessed that fewer than 50 were still living.

Twelve American citizens were taken during Hamas' Oct. 7 attacks. Two were released in late October, and two more were freed in November as part of a cease-fire deal. Of the eight Americans who remain detained in Gaza, four have been declared dead. U.S. and Israeli officials believe that four others could be alive.

More than 40,800 Palestinians have been killed and more than 94,200 others have been injured in Gaza since Oct. 7, amid Israel's ongoing ground operations and aerial bombardment of the strip, according to the Hamas-run Gaza Ministry of Health.

ABC News' Shannon K. Kingston contributed to this report.