Feds: Passenger had murder directions on computer

One publication was entitled "Man Trapping" and showed how to hunt and trap humans, she said. He also had a document with schedules for schools in Japan showing when students arrived and left.

The prosecutor detailed the discoveries during a court appearance by Harris, 28, a Boston University graduate who had been working in Japan as a junior-high teacher.

The bespectacled Harris was shackled in handcuffs and wore a white prison jumpsuit, along with a blue surgical mask over his mouth due to a throat infection.

Before the detention hearing, he crossed and rubbed his arms, appearing to be cold. He often turned and spoke with his attorney Steven Seiden.

U.S. Magistrate Judge Paul Abrams declared Harris to be a flight risk and ordered him held without bond until he stands trial.

Harris is charged with one count of transporting hazardous materials, for the grenade, and could face up to five years in prison if convicted. He did not enter a plea.