LINCOLN, Maine — A bomb threat that forced evacuation of Mattanawcook Academy last week was a hoax that likely will result in criminal charges, interim Police Chief Phil Dawson said Tuesday.

Investigators are examining evidence collected during their probe of the apparent hoax and will press charges if their investigation yields a likely suspect, Dawson said.

“We are now going through the process of determining who the author of that is. We have a list of names that we are currently looking to eliminate [as suspects],” Dawson said. “I can tell you that it will be no less than a terrorizing charge.”

Terrorizing is a Class C felony punishable by up to five years in prison and a fine of up to $5,000 for adults, according to Maine statutes.

The incident began about 1 p.m. Friday when a student noticed writing indicating a bomb threat on a boys restroom wall. The student informed school officials, and the principal ordered the school’s evacuation shortly thereafter, Dawson said.

Police and firefighters responded, and police searched the school, finding nothing, Dawson said. No one was injured during the evacuation.

The incident is at least the sixth false bomb threat to force the emptying of a school, school lockdown or school dismissal for a day in the Katahdin and Lincoln Lakes regions since 2006. Incidents previously have been reported at MA, Lee Academy and schools in East Millinocket and Millinocket.

Two students at Lee Academy, both juniors and juveniles, were charged with terrorizing in connection with an incident at Lee in 2007. Lee Academy is a private institution for grades nine to 12 with day students and students living on campus. It also has a postgraduate program.

Northern Maine Community College in Presque Isle also was closed Friday by several threats. Presque Isle police continued that investigation.

“We take this very seriously. It’s a disruption of the whole educational process, and it’s a danger to the people who have to respond to hoaxes. It creates an unnecessary risk,” Dawson said.