reporter: josh haskell, abc 7 news. larry: police say a campbell man may have helped prevent multiple mass shootings. he was honored today. officials hope this can be a lesson for everyone. dustin dorsey has the story. reporter: in a split second, a signal -- a single decision could change everything. >> after midnight on july 9, 2021, mr. mama doc called campbell police to say a man he could see on his security camera was prowling in the area. >> i was shocked. you never think it would happen in your own town, yet along your own business. i'm really glad i made that call. reporter: he and the responding police officers are being hailed as heroes for their actions that day. the prowler, wesley charles martin's, was arrested inside of his truck, a pipe bomb, ar style rifles and a racist manifesto which stated a desire to "wipe out the black, hispanic, and jewish populations." >> they found ammunition that was personally inscribed with to a widow from the grim reaper. a good start. first of many. and heard around the worl