The Justice Department on Wednesday charged former Cuban President Raul Castro with murder over his alleged role in shooting down two planes that were carrying humanitarian aid in 1996, according to a newly unsealed court docket. The shootdown resulted in the deaths of three Americans.

The indictment charges Castro with seven counts including conspiracy to kill U.S. nationals, destruction of aircraft and murder for each of the four passengers aboard the planes being flown by Brothers to the Rescue, a group that conducted rescue missions for Cuban exiles who sought to flee the country.

It marks a major escalation in the United States’ ongoing pressure campaign to achieve regime change of the island nation’s Communist-led government, though it’s not immediately clear whether the 94-year-old Castro will ultimately see the inside of a U.S. courtroom.

The indictment was returned by a grand jury on April 23 and unsealed today, Acting Attorney General Todd Blanche said at a press conference in Miami, Florida.

“For the first time in nearly 70 years, senior leadership of the Cuban regime has been charged in this country, in the United States of America, for acts of violence resulting in the deaths of American citizens,” Blanche said. “Nations and their leaders cannot be permitted to target Americans, kill them, and not face accountability. President Trump is committed to restoring a very simple but important principle: if you kill Americans … we will pursue you no matter who you are, no matter what title you hold, and in this case, no matter how much time has passed.”

He added, “The United States government has not forgotten these innocent men who were shot out of the sky.”

Brothers to the Rescue, a Miami-based organization, conducted humanitarian flight operations across the Florida Straits to search for Cuban migrants in distress, according to the Justice Department. U.S. officials allege that Cuban intelligence agents infiltrated the organization in the early 1990s and “relayed detailed information about its flight operations back to the Cuban government.” This information was used by Cuban military leadership in planning the Feb. 24, 1996, operation, U.S. officials claim.