A Turkish man pleaded guilty today to interfering with a flight crew and blamed his inflight behavior that prompted fighter jets to escort the plane to its Honolulu destination on a hallucination that he was chasing a butterfly.

A butterfly suddenly came out of the pocket of the seat in front of him, Anil Uskanli said in a Honolulu federal court today in describing what he did during the May 19 American Airlines flight from Los Angeles. “The butterfly went crazy … flew into the toilet,” he said. “I followed it. I tried to kill it by punching it.”

Uskanli, 25, said he now realizes that he was ill and hallucinating.

To flight crew and passengers, Uskanli’s behavior was concerning, including when he walked to the front of the plane with a blanket wrapped around his head and carrying a laptop that crew members feared contained explosives, Assistant U.S. Attorney Thomas Brady said.

After Uskanli returned to his seat and with an off-duty police officer sitting with him, the laptop remained on a drink cart, which prompted the captain to initiate bomb-threat procedures, Brady said.

The Hawaii National Guard scrambled two fighter jets to escort the plane to Honolulu. The secretary of Homeland Security was briefed.

Uskanli raised other red flags while still at Los Angeles International Airport, but experts said a lack of communication and an airline’s hesitancy to be caught on video booting a passenger played a role in allowing him to fly. In April, a United Airlines incident in which a passenger was dragged off an overbooked plane drew widespread attention.

Uskanli had purchased a ticket at an airline counter in the middle of the night with no luggage and was arrested ahead of the flight to Hawaii after opening a door to a restricted area. Airport police said he smelled of alcohol but was not intoxicated enough to be charged with public drunkenness, so he was given a citation and released.

After the flight landed in Honolulu and Uskanli was arrested, a judge ordered a mental competency evaluation at the request of his defense attorney. He was sent to a federal detention facility in Los Angeles to undergo the evaluation.

When Uskanli returned to Honolulu, defense attorney Richard Sing tried to have a hearing on his mental competency and detention closed to the public. U.S. Magistrate Judge Kenneth Mansfield initially granted the request. The Associated Press, Honolulu Star-Advertiser and other media objected, urging the judge not to limit the public’s right to court access without following proper procedures.

At a hearing last month, when lawyers representing the media were prepared to argue against closing the courtroom, Sing withdrew the motion, saying his concerns could be addressed without closing the entire proceeding. That allowed the hearing to move forward in open court.

Assistant U.S. Attorney Morgan Early argued that Uskanli should be held without bail because he’s a danger to the community and suffers from a “major mental illness.” Mansfield ruled that he was competent for trial and must be held without bail.

Today’s hearing was delayed by about two hours because a Turkish interpreter, was late. When the hearing finally got underway, U.S. District Judge Derrick Watson abruptly left the bench and seemed frustrated over the interpreter’s apparent inability to effectively translate the proceeding.

When Watson returned to the courtroom, he continued with the proceeding without using the interpreter and told Uskanli to use her if necessary. The lawyers in the case had requested the interpreter as a precaution even though Uskanli reads, speaks and understands English.

Uskanli’s student visa had been revoked because he wasn’t attending school, his immigration attorney Gary Singh said today. Uskanli faces deportation proceedings, but he plans to return to Turkey on his own, Singh said: “He just wants to go home. He’s sick and wants to go home to get help.”

He faces a maximum sentence of 20 years in prison and a fine of up to $250,000. But prosecutors don’t expect to ask for more incarceration than the time Uskanli has already served.