Full of youthful energy, the 80-pound Vader bounds out of the police car ready for work. Garden Grove PD Master Officer Edgar Valencia leads Vader to the area the K9 will search. In a matter of seconds, the 2-year-old black German shepherd finds what he’s looking for: the scent of bullet casings. After giving Vader his reward — a quick tug-of-war with a prized toy — Valencia continues walking. Just as quickly as the first, Vader finds his second target: this one is the scent of ammunition powder. “Vader will now alert to guns, live ammunition, spent casings, and black…