On this episode, Dennis sits with special guests, Keith Knotek and Mario Oliveira. Keith and Mario talk about their new book "Gunrunner: the Mario Oliveira Story", a true crime book centered on a real-life Boston area detective hero, Mario Oliveira, who embarks on a series of interconnected gang crimes that leads to his own murder. It's during death that he learns his most important lesson. To purchase "Gunrunner" visit: https://www.amazon.com/Gunrunner-Mario-Oliveira/dp/1948278510 Check out Mario's organization "VIPO" here: https://vipo911.org If you like what you are hearing and want to stay in the loop with the latest in Street Cop Training, please follow our Facebook Page: https://www.facebook.com/StreetCopTraining