A U.S. citizen accused of abandoning his birth nation to fight for al-Qaida was to be put on trial Tuesday, a day after the 16th anniversary of the Sept. 11 terror attacks, in a case that hinges partly on fingerprints found on an unexploded bomb.

Muhanad Mahmoud Al Farekh, who was born in Houston and raised in Dubai, was captured by security forces in Pakistan in 2014. His case has drawn extra attention because of reports American officials had debated whether to try to kill him in a drone strike, a step almost never taken against U.S. citizens. The administration of President Barack Obama ultimately decided to try for a capture and civilian prosecution instead.

Farehk, 31, has pleaded not guilty to conspiracy to murder U.S. nationals, conspiracy to use weapons of mass destruction and other crimes. There was no response to a request for comment from his defense team.

Most the charges against Farehk stem from an attack at Forward Operating Base Chapman in Khost City, Afghanistan, on Jan. 19, 2009, involving two vehicles rigged with explosives and driven by suicide bombers. An initial blast injured several Afghans, including a pregnant woman, but a much larger bomb failed to go off, sparing the lives of American soldiers.

Forensic technicians in Afghanistan recovered 18 of Farehks’ fingerprints on adhesive packing tape used to bind the explosives on the unexploded bomb, prosecutors said in a court filing.

A jury was to hear about the evidence at opening statements Tuesday in federal court in Brooklyn.

Before Farekh’s capture in Pakistan, the Pentagon nominated him for a kill list for terrorism suspects, with CIA officials also lobbying the White House to authorize his killing, according to a report in The New York Times. But the Department of Justice pushed back, questioning whether he was a big enough player in the terror network to take the extraordinary step of killing an American overseas without a trial.

President Donald Trump’s administration has taken steps to give the CIA and the military more latitude to target and kill al-Qaida and Islamic State group militants without presidential sign-off in places including Yemen, Somalia, Iraq, Syria, Libya and Afghanistan.

Attorney General Jeff Sessions has argued Guantanamo Bay, a U.S. military base in Cuba, is the best place to try terror suspects, saying civilian courts give legal protections to which they are not entitled.

During the presidential campaign, Trump, a Republican, said he wanted to keep the detention center in Cuba open after Obama, a Democrat, had long fought to close it. Trump promised to “load it up with some bad dudes.”