PORTLAND – The lawyer for a Florida man accused of causing a trans-Atlantic flight to be diverted to Maine is exploring the man’s use of Ambien, but said it’s too early to say whether the sleep aid caused his actions.

Derek Stansberry’s behavior on the Paris-to-Atlanta flight was out of character, said defense lawyer Virginia Villa.

The former Air Force intelligence specialist handed a rambling note to flight attendants that said his passport was fake and then told an air marshal that he had dynamite, according to court documents.

Stansberry, 26, of Riverview, Fla., was on the April 27 flight while returning from his work for a defense contractor in Burkina Faso..

According to his father, Stansberry had a prescription for Ambien, which is often used by travelers to sleep on long flights. Ambien’s rare side effects include confusion and agitation.