The alleged mastermind of the Sept. 11, 2001, terrorist attacks was angered when he learned he had to undergo security screening between flights on the morning of the suicide attacks, a former U.S. Airways ticket agent says.

Michael Tuohey of Scarborough said he was suspicious of Atta and Abdulaziz Alomari when they rushed through the Portland International Jetport to make their flight to Boston that day.

Atta’s demeanor and the pair’s first-class, one-way tickets to Los Angeles made Tuohey think twice about them.

“I said to myself, ’If this guy doesn’t look like an Arab terrorist, then nothing does.’ Then I gave myself a mental slap, because in this day and age, it’s not nice to say things like this,” Tuohey told the Maine Sunday Telegram. “You’ve checked in hundreds of Arabs and Hindus and Sikhs, and you’ve never done that. I felt kind of embarrassed.”

In Boston, Atta and Alomari joined three other hijackers on American Airlines Flight 11, which they crashed into one of the World Trade Center’s twin towers in New York. Five other hijackers left Boston on another flight, which they crashed into the other tower.

Tuohey, 58, who retired last year, said he was speaking out because his exchange with Atta was included in recently declassified material that had not been included with the 9/11 Commission’s initial public report. His exchange was included in order to shed light on why Atta chose to fly to Boston from Portland.

One-step check-in

Investigators’ leading theory for Atta’s decision to start his day in Portland, about 100 miles from Boston, was that he wanted to avoid suspicion that might arise if all of the hijackers arrived at once at Boston’s Logan Airport.

But his decision meant that he had to go through security screening once in Portland and again between flights in Boston, because he had to take a bus and switch terminals.

Tuohey said Atta became angry when he was told he would have to check in again before boarding his flight out of Boston.

“He looks at me and says, ’I thought there was one-step check-in ... They told me one-step check-in,”’ Tuohey said. “I looked in this guy’s eyes, and he just looked angry. I just got an uncomfortable feeling.”

“It just sent chills through you. You see his picture in the paper (now). You see more life in that picture than there is in flesh and blood,” Tuohey said.

After the attacks, Tuohey was interviewed by an FBI agent. As he watched a security video, he picked out Atta and Alomari without a doubt, he said.

A few weeks later, another investigator showed him a large number of pictures and asked him to point out the men he had waited on that day.

“I went right to Atta,” Tuohey said. “It’s like the skull on a poison bottle. There’s no mistaking that face.”