Students in Maine School Administrative District 75 schools have the day off Friday because 575 staff members across seven district schools will be taking part in an active-shooter response training.

Active and retired police officers, SWAT team members, lawyers, police chiefs and school resource officers will participate in the training, so locals are likely to see an unusual number of emergency vehicles at the schools.

The training, led by Dirigo Risk Management Solutions, is expected to last about four hours. Interactive video presentations and tabletop exercises will be used to instruct staff about a range of topics, including a history of active threat and mass casualty incidents in schools, risk factors, situational awareness, response guidelines, communication strategies, and pre-planning measures.

Mt. Ararat Middle School was subject to two bomb threats last month — one on Sept. 17 and another the following day. Police are still looking for a suspect.