While I agree Terzuola is an early proponent, I think several makers in the eighties began making the knives we now call "tactical". Its like asking who invented rock 'n' roll - no one individual did it. Clearly, by the mid- to late 1980's the breed came into being. That ground swell turned into a breaking wave with the advent of chisel ground tantos, Bob's thumb discs, and adopting Walker's liner lock in titanium. The funny thing is now everyone is making these same no-frills workers in damascus, pearl, etc.