In a world where threats can emerge without warning, A Good Guy with a Gun: A Case for Concealed Carry by retired police detective Mike Diamond offers a powerful, evidence-based defense of responsible firearm ownership and the right to self-protection. Drawing from over 30 years on the force-chasing criminals, investigating crime scenes, and witnessing the human cost of violence-Diamond shares real-life stories of everyday heroes who turned the tide against aggressors using legally carried guns. From personal encounters with muggers and home invaders to family defenses during break-ins and bystander interventions that halted active shooters, the book dissects these high-stakes moments: the defenders' backgrounds and training, the rapid escalation of danger, and the split-second decisions that saved lives. But it doesn't stop there-Diamond explores the aftermath, including legal battles, emotional recovery, media scrutiny, and psychological impacts, while addressing training essentials, ethical dilemmas, and the societal benefits of concealed carry, such as deterring crime through uncertainty and empowering the vulnerable. Far from glorifying violence, this book illuminates a simple truth: a prepared, good guy with a gun can stop a bad guy, often filling the gap where law enforcement can't arrive in time. With rigorous analysis grounded in verifiable cases, statistics, and the author's firsthand insights, it's a call to embrace self-reliance in an unpredictable world. Ideal for gun owners, skeptics, policymakers, and law enforcement professionals seeking facts over fear.