Police say a 21-year-old New Hampshire man who triggered a 90-minute lockdown at his former high school when he showed up with a gun tucked into his waistband had wanted a letter of recommendation from a teacher.

Damian Johnson of Manchester was arraigned Friday on a felony count of falsifying physical evidence and misdemeanor counts of criminal trespass, violation of probation and disrupting school in session. He was jailed on $20,000 bail.

Police say a student at Manchester High School West reported seeing Johnson with the gun Thursday, prompting the lockdown. It turned out to be a pellet gun. He was found in a small, occupied classroom and was arrested without incident.

Manchester Police Chief David Mara said Johnson never made a threat or acted violently.