The CIA concluded that former Chilean dictator Augusto Pinochet personally ordered the 1976 murder of a top dissident, according to newly released government documents that show U.S. confidence about a key ally’s responsibility for a shocking attack in Washington.

The latest revelations about the Cold War-era case come on the 40th anniversary of the assassination of Orlando Letelier, a leading opponent of the Pinochet regime and onetime Chilean foreign minister, and his think-tank colleague, Ronni Moffitt, in a car bomb on D.C.’s Embassy Row.

The case set off a complex international investigation that concluded with the conviction of several key suspects but did not touch the most senior level of Chile’s U.S.-backed government.

The CIA assessment released Friday is part of a suite of documents presented in 1987 to President Ronald Reagan by his national security adviser, Frank Carlucci, regarding U.S. government policy on Chile.