My son, 18yo, was stopped for speeding on the freeway in washington state. He was going 10 over the limit. He had a knife with him, in the car, that was apparently illegal, although he had no idea it was illegal.. It was not hidden, or on his person, but in the center console. The trooper did not see it, but my son, believing you should always tell an officer if you have a weapon in the car told him..and gave the knife to the officer when he asked for it. He was cited for dangerous weapon RCW 9.41.250. I know ignorance is not a viable defense but what should my son do, or expect. He is really worried about this.