Lt. Col. Roberto Hernandez Caballero, assigned to the state security division of the powerful Interior Ministry, told the jury he was in charge of a task force that investigated a series of bombings in Havana and the beach resort of Varadero that ran from April to October 1997.
Prosecutors accuse Cuba-born Luis Posada Carriles of lying during citizenship hearings in El Paso about how he sneaked into the U.S. in March 2005, and of failing to acknowledge planning the bombings of Cuban hotels and a top Havana tourist restaurant in 1997.
Posada told the New York Times in 1998 that he was behind the bombings, which he said were meant to hurt Cuban tourism - but that no one was supposed to have been killed. He has since recanted those comments.
The 82-year-old - who spent decades as a Washington-backed Cold Warrior, traversing Latin America to foment violence - faces 11 counts of perjury, obstruction and immigration fraud.
Italian Fabio Di Celmo, 32, was killed when a bomb tore through the lobby bar at the Hotel Copacabana on Sept. 4, 1997, and about a dozen other people were wounded in other attacks.
Hernandez described how that bomb destroyed a crystal ashtray, sending shards of glass flying that killed Di Celmo. One photograph showed how the explosion reduced part of a wooden bar into a charred pile of boards and ornate paneling, another focused on a blood stain on the floor amid a collection of high-backed, wicker chairs.
"You could see a lot of destruction and the shrapnel from the ashtray," Hernandez said. For emphasis, prosecutors had him circle the blood stain on a digital reproduction of the photo.
"It was a large stain of blood," said Hernandez, who testified through an interpreter.
The white-haired Posada displayed no emotion and appeared at times to have trouble staying awake.
Hernandez's testimony was a rare measure of cooperation between Cuba and the U.S., two governments usually paralyzed by nearly a half century of ice-cold relations. Washington's trade embargo against the island turns 49 this month.
Posada is not on trial for the bombings, only for lying about them at his immigration hearings. His answers under oath during those proceedings prompted the current charges against him.
Still, he is Public Enemy No. 1 in Cuba, considered ex-President Fidel Castro's personal nemesis, and island authorities have been more than willing to cooperate in the case against him. In addition to Hernandez, a Cuban medical examiner who performed an autopsy on Di Celmo is set to testify, and a third Cuban police official may also take the stand. Cuba also provided U.S. attorneys with 6,500 pages of documents on Posada.
Hernandez answered prosecutors' questions in serious tones with little commentary. The process moved slowly because the defense raised objections about every one of the more than a dozen photographs from different bombing scenes that he showed while testifying.
Many were dark and blurry, and none more dramatic than the Copacabana's wooden floor stained with blood.
Hernandez seemed to contradict himself about the time of the explosion that killed Di Celmo, saying at first that it occurred at 12:10 p.m., but saying later it was about an hour earlier.
He also testified that another bomb exploded 10 minutes later at the Chateau Miramar, a small hotel nearby. No one was injured in that attack, but a large fish tank was pulverized.
In recounting other 1997 attacks, Hernandez described how a bomb exploded in a bathroom sink inside the discotheque of the Melia Cohiba Hotel around 3 a.m. on April 12. At the time, the hotel was the most-popular among tourists visiting Havana.
He told how an explosion rocked the lobby, blowing apart a couch and smashing windows, at Havana's Hotel Capri on July 12, and how, five minutes later, a bomb destroyed a bank of phone booths at the iconic Hotel National. He talked about the Aug. 22 bombing of the hallway linking the rooms and lobby in the Sol Palmeras Hotel in Varadero, a resort of powder-white sand east of Havana, and another that blew up that same month near the reception desk of the Melia Cohiba, a hotel which Castro had personally inaugurated when it opened in 1994.
A paid CIA agent from 1964 until 1976, Posada participated indirectly in the Bay of Pigs invasion and later moved to Venezuela, where he served as head of that country's intelligence service. He was arrested for planning the 1976 bombing of a Cuban airliner that killed 73 people. A Venezuelan military court dismissed the charges, but Posada escaped from prison before a civilian trial against him was completed.
In the 1980s, he helped Washington provide aid to the Contra rebels in Nicaragua. In 2000, he was arrested in Panama in connection with a plot to kill Castro during a summit there. He was pardoned in 2004 and turned up in the U.S. the following March.
Posada was held in an immigration detention center in El Paso for about two years but released in 2007 and has been living in Miami. Cuba and Venezuela would like to try him for the 1976 airliner bombing and the 1997 hotel attacks, but a U.S. immigration judge has previously ruled Posada can't be sent to either country for fear he could be tortured.