Moen called 911, and a police officer soon arrived. The officer saw the screen shot, then called her chief, who sent two detectives to Moen’s house. The detectives collected some information about the person who posted the threat. They then returned to their office, where they made an emergency records request for account information, which allowed them to determine the sender’s email and IP address, which was traced to Port Huron, Mich.

The detectives called police in Michigan, who immediately drove to the house where the threatening message originated. When the police arrived at the address, they found a 14-year-old boy, who, they said, admitted to posting the threat. They also found two rifles that belonged to his mother, according to Capt. Joseph Platzer of the Port Huron Police Department.

Platzer said the boy’s threat was aimed at the middle school that he attends in a nearby township. The boy was taken to a juvenile-detention center, where he remains. He was charged with making a false report of a threat of terrorism, a felony that is punishable by up to four years in jail.