(STMW) — A 15-year-old student at Hinsdale Central High School has been charged with bringing an unexpended shotgun shell to school, prompting a brief lockdown Friday.

The student, who lives in unincorporated Clarendon Hills, faces one count of possession of ammunition, a misdemeanor that will be petitioned through the juvenile court system, according to Hinsdale police.

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School officials and police issued the lockdown about 11:45 a.m. after someone found the piece of ammunition, which had been left in the cafeteria, according to a joint statement from Hinsdale Police and School District 86.

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Investigators determined there was no danger to students or staff and the lockdown was lifted about 1:20 a.m., the statement said.

Students and staff “sheltered in place,” during that time, police said previously. Classes continued, but movement inside and outside the building was restricted.

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(Source: Sun-Times Media Wire © Chicago Sun-Times 2015. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)