Authorities won't prosecute a University of South Florida student who announced on a campus bus he was carrying a bomb.

Vincent McCoy was arrested last month after another student's bomb threat caused a three-hour campus lockdown.

According to prosecution documents, the 23-year-old said "I got the bomb right here — no sudden moves," after a school employee announced the lockdown.

Witnesses said McCoy sounded like he was kidding, and made the statement after the employee asked if anyone had a David Letterman joke.

The man accused of making the first threat, 26-year-old Markenson Innocent, will be prosecuted. He was charged Tuesday with disrupting a campus function and making a false bomb report against state-owned property.

McCoy remained jailed on an unrelated theft charge.

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