A 17-year-old was arrested on two counts of terroristic threats, which police say were made toward Millard South on Tuesday .
The threat was initially considered unsubstantiated.
The suspect's name was not released.
Stay with 3 News Now for more on this story as it develops.
Correction: The original story stated the suspect arrested was a Millard South student, which was not the case. 3 News Now regrets the error.