The Trump administration said it was protecting Americans unjustly held abroad. One of the rescued men, Dahud Hanid Ortiz, killed three people, according to court documents.

When the State Department secured the release of 10 Americans and permanent legal residents from a Venezuela prison last week, Secretary of State Marco Rubio hailed the action as part of an effort to safeguard the well-being of Americans unjustly held abroad.

But one of the men released from the prison, an American-Venezuelan dual national named Dahud Hanid Ortiz, had been convicted in Venezuela for the murder of three people in Spain in 2016, according to an official at the prosecutor’s office in Madrid and Venezuelan court records reviewed by The New York Times.

The official asked not to be identified speaking publicly about the case.

Mr. Hanid Ortiz, 54, had served 19 years in the in United States Army, according to military documents, and had been awarded a Purple Heart for injuries received in Iraq. He had multiple deployments and suffered physical and mental injuries as a result of his service, according to the Army. He was later dismissed from the military after pleading guilty to fraud and larceny.

Then, in 2023, he was sentenced to 30 years in prison for a triple homicide committed in Madrid in 2016, according to Venezuelan court documents and Spanish news media coverage.

The court records say that Mr. Hanid Ortiz had planned to murder a lawyer in Madrid who had a relationship with his wife. But on the June day in 2016 when he arrived at the lawyer’s office and did not find his target, he killed two women there, as well as a man who he mistakenly believed was the lawyer.

The deaths were violent, according to an extradition request by the Spanish government that was included in the Venezuelan records. One of the women, Elisa Consuegra, was killed with a large knife or machete. The second woman, Maritza Osorio, and the man, were likely killed with an iron bar. Afterward, Mr. Hanid Ortiz lit the office on fire in an attempt to cover up his crime, then fled to Germany and eventually to Venezuela.

On Wednesday, the lawyer who was the intended target of Mr. Hanid Ortiz’s attack, Victor Salas, said in an interview that he was alarmed to find that the United States had facilitated Mr. Hanid Ortiz’s release from a Venezuelan prison.

Mr. Hanid Ortiz arrived Friday in the United States, but it is not clear if he is free or in U.S. custody, leaving Mr. Salas fearful that the convicted man would come after him.

“I am completely defenseless right now,” he said. “I believe Dahud has taken advantage of Venezuelan corruption and American negligence.”

Juan Carlos Consuegra, 69, the father of Ms. Consuegra said that he was shocked by the actions of the Trump administration.

“I don’t understand how it’s possible that this happens,” he said. “This guy is a delinquent. He’s an assassin.”

The Spanish government had previously attempted to extradite Mr. Hanid Ortiz from Venezuela, but the Venezuelan Constitution prohibits the extradition of Venezuelan citizens. This led Mr. Hanid Ortiz to be tried inside Venezuela, which allows Venezuelans to be tried for crimes committed outside the country.

President Trump has made deporting criminals from the United States a core promise of his tenure. In recent months his government had sent more than 250 Venezuelan men to a prison in El Salvador, accusing them of being dangerous gang members and a threat to the nation. The Trump administration has provided little evidence to back up this claim.

On Friday, Mr. Trump agreed to approve the release of the men in El Salvador in exchange for 10 Americans and U.S. legal permanent residents who had been held by the government of Nicolás Maduro, Venezuela’s autocratic president.

Family members of some of the men returned to the United States have said their loved ones had traveled to South America as tourists, and were then nabbed by Venezuelan authorities.

“Every wrongfully detained American in Venezuela is now free and back in our homeland,” Mr. Rubio said after the swap.

The State Department did not respond to questions on Wednesday about why the administration had decided to include Mr. Hanid Ortiz among those freed from Venezuelan detention, whether the U.S. government knew of his crimes, and whether Mr. Hanid Ortiz was allowed to go free once he was on U.S. soil.

In a statement, a spokeswoman for the State Department said: “The United States had the opportunity to secure the release of all Americans detained in Venezuela, many of whom reported being subjected to torture and other harsh conditions.”

For “privacy reasons,” the spokeswoman said, more information was not being released.

The Venezuelan court records documenting Mr. Hanid Ortiz’s crimes and conviction are publicly available on the website of the country’s highest court.

Giselle Caso, who described herself as Ms. Consuegra’s best friend, said family and friends were appalled to see Mr. Hanid Ortiz in photos released by the State Department on Friday, smiling in civilian clothes, appearing to be prepared for a life of freedom.

“We want to know: Under what terms was this man released?” she said. “Is the United States going to make him serve out his prison term?”

“This is not a political prisoner,” she added.

“These people were tortured,” Ms. Caso said. “They weren’t shot with a pistol, they were killed with a knife, and then the place was set on fire. It was a horrible way to die.”

In the extradition request, Spanish authorities say that Mr. Hanid Ortiz sent an email to his wife’s sister after the murders, in which he confessed: “I did terrible things.”

“I am responsible for everything and now I am bad, I lost my head and I stopped thinking,” he wrote. “No one will every forgive me for what happened.”

Mr. Hanid Ortiz served 17 years in the U.S. Army as an enlisted soldier followed by two years as a commissioned officer. Beyond the physical and mental injuries he suffered on the job, he also had disciplinary problems, according to the Army.

Late in his career, the Army charged him with larceny, malingering, and making false official statements, accusing him in a court-martial of submitting false physical and medical information and of falsifying recommendations from his superiors in his application to become a commissioned officer.

They also accused him of lying about where he lived so that he could receive housing assistance, saying that he received more than $87,000 in compensation that he was not entitled to.

A military judge ordered him jailed for six months, fined $25,000 and forced out of the Army. Mr. Hanid Ortiz appealed, but two military judges upheld the decision in 2015.

Mr. Salas, the lawyer, said that he had initially learned about Mr. Hanid’s release from German police, who had heard the news and were concerned about the security of the convicted man’s ex-wife, who is a German citizen.

“They consider Dahud to be a highly dangerous person,” said Mr. Salas.