ARAPAHOE COUNTY, Colo. — Arapahoe High School in Centennial was placed on secure perimeter Friday due to what the district said was an anonymous 911 call claiming that there was a potential threat of a gun being brought to school. 

The Arapahoe County Sheriff's Office said it now believes the call was a hoax. During the secure perimeter, class continued as normal but no one was allowed to enter or leave the school, which is at the corner of East Dry Creek Road and South University Boulevard. 

The perimeter was enacted at around 11:30 a.m. and lifted at around 12:40 p.m., according to a letter distributed to parents. Deputies cautioned the community to avoid the area while this was in place. 

This investigation came in addition to heightened police activity in the area due to an "unrelated event," the letter said. 

This placed five nearby elementary schools on a secured perimeter as well. 

Those schools were: 

  • Carl Sandburg Elementary 
  • Mark Twain Elementary 
  • Franklin Elementary 
  • Highland Elementary
  • Hopkins Elementary

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