An 18-year-old man whose alleged threatening emails to an employee at North Whidbey Middle School caused a lockdown earlier this month was charged with a felony, according to court documents.

Prosecutors charged Charles S. Ferguson in Island County Superior Court Oct. 14 with one count of harassment — threats to kill.

If convicted, he could face from three to eight months in jail under the standard sentencing range.

Ferguson was being held in jail in lieu of $20,000 bail.

In a report on the incident, Officer Robert Dickinson with the Oak Harbor Police Department wrote that the Oak Harbor School District notified police Oct. 9 that the middle school was being locked down because of threats against a staff member.

Ferguson sent a series of text messages to a family member who works at North Whidbey Middle. The messages stated that he “was going to harm her and that … he had a gun,” the officer said in his report.

The alleged victim said she and Ferguson recently moved to Oak Harbor and he was upset there were other people living in their home, the report said.

Nine of the text messages are included in the police report.

In one text, Ferguson allegedly said that he obtained a gun from a friend. In another text, the report said, Ferguson wrote that he was thinking about going on a “killing spree.”

Ferguson doesn’t mention the school in any of his text messages, but focused his anger at the alleged victim and the people living in the house.

He wrote that he would “have no regrets killing everyone in this house,” the police report states.

The alleged victim said she suspected that Ferguson could carry out his threat and “believes he is unstable,” Dickinson wrote.

The report states that the lockdown caused a serious disruption in the release schedule for the school.