CBS News correspondent Bob Orr reports the Massachusetts Institute of Technology sophomore told police she was there to meet a passenger arriving on a Continental flight from Oakland. She explained her get-up saying, "I wanted to stand out in the crowd."
Star Simpson, 19, allegedly had a computer circuit board, wiring and a putty that later turned out to be Play-Doh in plain view over a black hooded sweatshirt she was wearing, said State Police Maj. Scott Pare, the commanding officer at the airport.
After a Massachusetts Port Authority official notified State Police about 8 a.m., troopers tracked Simpson down outside Terminal C, where they arrested her and later determined the device was a fake.
"She's extremely lucky she followed the instructions or deadly force would have been used," Pare told The Associated Press. "And she's lucky to be in a cell as opposed to the morgue."
Simpson is from Hawaii, officials said.
Tim Anderson, a colleague at MIT, knows Simpson personally and told CBS radio station WBZ that what happened at Logan Airport is likely being blown out of proportion.
Simpson was to be arraigned in East Boston District Court later in the day. She's charged with disturbing the peace and possessing a hoax device.
A Massport staffer manning an information booth in the terminal, home to United Airlines, Jet Blue and other carriers, became suspicious when Simpson - wearing the device - approached to ask about an incoming flight, Pare said. Simpson then walked out of the terminal and the information booth attendant notified a nearby trooper.
The trooper, joined by others with MP-5 submachine guns, confronted her at a traffic island in front of the terminal.
Pare said Simpson took an MBTA subway to the airport, but he was not sure if she had the device on at that time. She was arrested near an area where shuttle buses arrive to take passengers back to the airport subway station.
"She was allegedly picking somebody up," said Pare.
The major praised the booth attendant but said the incident is a reminder of the terrorism threat confronting the civil aviation system. Two passenger jets were hijacked from Logan on Sept. 11, 2001, and later flown into the World Trade Center as part of a broader terrorist attack that crashed other jets into the Pentagon and a field in Pennsylvania.
Nearly 3,000 died in the attack, and Logan has since become a model and test bed for many aviation security techniques.
Orr reports officials say they had to take the incident seriously. All of U.S. aviation remains under Code Orange, the second highest terror threat level.
"In this day and age, the threat continues to be there," said Pare. "She certainly jeopardized her own safety by bringing this to the airport, as well as the safety of everybody around her."
A spokeswoman for MIT had no immediate comment.