Damon Gilbert has served the citizens of Oakland, California, as a police officer for more than two decades. Unlike many of his law-enforcement peers across the country, who often gravitate toward self-defense systems with reputations for being “hard core” or “close-combat oriented” — think krav maga, military combatives or even MMA — Gilbert trains in and teaches what could be regarded as a traditional martial art (inasmuch as “traditional” refers to anything that predates t