Federal prosecutors have charged a Long Island woman for calling in a fake bomb threat to a Southwest Airlines flight because she didn't want her mother and brother to fly close to the 10th anniversary of 9/11.

The criminal complaint says airport police in Tucson, Ariz. received an anonymous call from a woman on Sept. 10 saying she overheard her boyfriend and others discussing a plot to bomb Southwest Airlines Flight 2475 that day.

Police called bomb squad officials and notified the FBI. Law enforcement took all the luggage off the plane and searched the aircraft and bags while the passengers were double-screened. Security throughout the entire airport was increased, the complaint says.

The FBI's investigation led authorities to Mary Purcell, 37, in Lake Ronkonkoma, whose mother and brother were scheduled to be on the flight.

She eventually admitted to an FBI special agent that she made the threat because she didn't want her loved ones flying so close to the anniversary of 9/11, according to the complaint.

Purcell has a history of deceiving authorities: a law enforcement source told NBC New York she has four felony convictions, including one for forgery.

Purcell was charged Tuesday in Central Islip with a federal offense of making a false bomb threat over the phone. She was released on $200,000 bond. Coincidentally, it was her mother and brother who signed the bond -- the same family members she was allegedly trying to keep grounded in Arizona

Purcell was represented by a court-appointed attorney from the Federal Defenders. A representative of the Federal Defenders declined comment.