CASTLE ROCK, Colo. — Amid a week that's left the Douglas County School District shaken, Douglas County High School got a tip Thursday morning about a threat against an event at the school, but officials determined it wasn't valid.
Officials got the tip through the Safe2Tell app, Douglas County Sheriff's Office spokeswoman Cocha Heyden said.
The threat came just two days after the shooting at STEM School Highlands Ranch – another Douglas County school – which left one student dead and eight others injured.
Officials were unsure of the specific threat at Douglas County High School, but the sheriff's office determined it was just a rumor. The sheriff's office was still investigating the threat later Thursday morning.
Douglas County School District spokeswoman Paula Hans said the school canceled a morning assembly as the threat investigated, but no lockdown or lockout happened.
Additional security presence has been in place at Douglas County schools since the STEM school shooting, Hans said, and sheriff deputies were still at Douglas County High School later Thursday morning.
Heyden said threats against schools happen more often than some might realize and that investigators try to run down the tips each time.