A man walked into a California barbecue restaurant with a knife, already bleeding, and kept advancing after an armed citizen told him to drop it. This happened at Lucille’s Barbecue in Los Angeles County — inside a busy shopping center, in a sit-down restaurant full of regular people just trying to eat. That matters. Because the armed citizen didn’t just draw and fire. He gave the man a chance to drop the knife. He gave him a chance to stop. But when someone is holding a blade, ignoring commands, and still closing distance inside a room full of strangers, the...