WASHINGTON – The Trump administration's deadly strikes on boats off the coasts of South America – and the release of multiple survivors back to their home countries – have raised questions about who the U.S. killed and what evidence they had the vessels were transporting drugs.

Trump administration officials say the strikes are part of a sweeping counternarcotics operation. Pentagon Chief Pete Hegseth and other officials have said U.S. intelligence determined that the boats carried drugs and passengers on them were parties to criminal trafficking of illegal substances to the U.S.

To date, however, the Defense Department has provided no evidence. As concerns boil over from some lawmakers that these strikes are illegal, Trump administration officials have opted to withhold details, holding a memo justifying the military action close to their chest.

The answers to what officials know and how they know it are there, some have indicated, but the information is not yet accessible to anyone but Republican Senate insiders.

“One thing that's been highly misconstrued here is that in some way we don't know precisely who we're striking and why," Hegseth told reporters on Oct. 31.

"We know how to map networks and hunt enemies of our country, and in this case, that's what's happening."

After the administration briefed members of the House on the strikes on Oct. 30, Rep. Sara Jacobs, a Democrat from California, said she didn't have enough information to know whether the deadly strikes were justifiable. Trump officials "promised" they would send the memo to her and other lawmakers, but did not follow up, she told USA TODAY.

The military needed to show a "connection to a designated terrorist organization or affiliate" before an attack, "but that can be very broadly interpreted."

The boats are so wrecked after the strikes that any evidence they carried drugs has not been preserved, she said.

Return of survivors raises concerns

At least 61 people have been killed in the two months since the offshore attacks began. Three people have survived them, and two of them were returned to their home countries – Colombia and Ecuador.

Ecuadorian officials released the man who survived the U.S. hit from custody/detention, explaining that authorities did not have enough evidence to convict him of a crime.

The repatriated survivors raised a new legal question: if the U.S. had enough evidence to attack their boat, why wasn't that evidence sufficient to try them in an American court?

In the two months since the first U.S. strike killed 11 people on a vessel in the Caribbean, lawmakers in Washington have been pressuring the Trump administration for more information about the strikes and the legal justification for them.

Many of the targeted boats departed from Venezuela, and the strikes appear to be tied to a campaign led by Secretary of State Marco Rubio to force President Nicolás Maduro, the country's left-wing strongman, from power. President Donald Trump has said repeatedly that the next strikes could be on land – although he denied a Wall Street Journal report on Oct. 31 that the U.S. had a ready-to-go list of targets in Venezuela.

The legal memo providing the military's justification for the strikes was reportedly drawn up by the Justice Department – not the Pentagon. Taking that approach is something the CIA calls a "golden shield" within the CIA, Jack Landman Goldsmith, a senior fellow at the American Enterprise Institute, wrote in a commentary article. The document protects officials operating under it from criminal prosecution down the line, he wrote.

Jacobs and other Democrats in Congress said they were informed at the last minute that the military lawyers scheduled to speak to them on Oct. 30 would not show up.

"The Pentagon pulled its lawyers – the exact people who would supply a legal justification for these strikes – from the briefing with no notice," Rep. Seth Moulton, a Democrat representing Massachusetts, said on X.

A day earlier, the administration shared the legal memo with some Republican senators – an unprecedented move that provoked fury from Democrats. Both sides of the political aisle on the Hill are historically briefed as a uniform group.

"I don't have any freaking idea" why the legal rationale is classified, Democratic Sen. Mark Warner told reporters at the Capitol on Oct. 30. "If you've got a valid legal opinion, wouldn't you want to share it with every member?"

The strikes also have not targeted the central nodes of the networks that bring drugs into the U.S. Most illegal shipments of fentanyl, one of the deadliest contributors to drug overdoses in the U.S., enter the U.S. by land, from Mexico.

Cybele Mayes-Osterman covers national security and world affairs for USA TODAY. Reach her on email at cmayesosterman@usatoday.com or on cell/Signal at 505-702-6900.

This article originally appeared on USA TODAY: Who is the US killing in its boat attacks? Hegseth won't say, and lawmakers want answers.

Reporting by Cybele Mayes-Osterman, USA TODAY / USA TODAY

USA TODAY Network via Reuters Connect