In still waters

Years ago, in a high school in the quiet town of Austin, Minnesota, a tragic incident occurred. Years later, a series of horrific murders shakes the peaceful community. One by one, seemingly unconnected individuals fall victim to a mysterious killer dressed in black, their face hidden beneath a hood. How does this shadowy figure manage to evade the police, leaving no trace behind? What connection do they have to a gang of arms dealers operating in the shadows?