A California woman is in federal custody tonight after threatening notes found aboard a cruise ship bound for Hilo prompted the FBI and local law enforcement to divert it, board it, and search it for biological, chemical, radiological and explosive weapons. Kelley Marie Ferguson, 20, of Laguna Hills, Calif., has been charged under federal law relating "acts of terrorism transcending national boundaries."

"The defendant said that she never wanted to go on this cruise with her family to begin with, and that she wrote these notes hoping that it would shorten her time on the cruise, thereby allowing her to rejoin her boyfriend in Orange County, California," U.S. District Attorney Edward Kubo, Jr. told reporters at a briefing today.

Ferguson, who was traveling with her parents and two sisters, is facing two charges that require incarceration, and could face up to ten years in prison.

Two notes were discovered on the Royal Caribbean cruise ship Legend of the Seas last Wednesday, as it made its way from Ensenada, Mexico to the Big Island with about 2,400 passengers aboard. The notes read in part, "I have been sent on a mission to kill all Americanos abord [sic]... I will kill all. Do take us serious [sic]."

The ship was diverted to waters off Honolulu, and over 100 members of the federal and local Joint Terrorism Task Force boarded and searched the vessel, finding nothing to corroborate the threats in the notes. It was reportedly the largest law enforcement boarding of any cruse ship in history.

The FBI's Daniel Dzwilewski, Special Agent in Charge in Honolulu, said the substantial government response to the threatening notes was the only proper response given the times. "You didn't know the nature of the threat," Dzwilewski said.

The ship was released by authorities Thursday morning.

Investigators said a third note was discovered that specifically threatened Ferguson, in an apparent attempt to throw them off. According to the FBI, she ultimately confessed to writing the notes in an interview on Friday and was arrested the next day while the ship was docked in Maui.

But Kubo said he was most troubled by the sense that Ferguson didn't seem to understand the seriousness of what she did.

"I find it very disturbing that after causing all this fear, excitement and concern, the defendant never showed any degree of regret or remorse for her actions, not even after her arrest," he said. "We do not consider such threats to be jokes, and if you commit such an act and disrupt lives, we will use all of our resources to investigate and prosecute you."

Ferguson is expected to appear in federal court for a detention hearing on Thursday.