A high school and a middle school in Woodland Hills were locked down today after a school policeman was shot and a manhunt got under way for man described as possibly in his 40's. The officer was wearing body armor, and was hospitalized in fair condition. Meantime, students at Gardena High School had to line up on the sidewalk for screening this morning, a policy that was not followed yesterday. That's when an automatic weapon brought on to the campus in a backpack accidentally discharged when the bag was laid down on a desk. The boy and girl who were hit are still in stable and critical condition respectively. The boy with the backpack faces charges of assault with a deadly weapon. This morning's Los Angeles Times carried a column by Steve Lopez under the headline, "It's time to inject sanity into the gun debate."