Massachusetts school to debut 'active shooter' system METHUEN, Mass. - The city says one of its schools will become the first in the nation to deploy an automated system to detect and track a gunman on campus. Methuen Mayor Stephen Zanni and other city officials will attend a demonstration of the technology developed by Massachusetts-based Shooter Detection Systems on Tuesday afternoon. The demonstration will simulate an active shooter in a school building and a police response using the technology. The smoke alarm-sized system will give police a shooter's exact location in real time. School officials say the investment will dramatically improve current school lockdown procedures. New England saw one of the worst school shootings in U.S. history when a 20-year-old gunman killed 26 children and adults at an elementary school in Newtown, Connecticut, in December 2012.