Charlie Kirk is shot and killed at an event he was hosting at Utah Valley University. Ken Dilanian, Andrew Weissmann, Brigham Tomco, Ryan Reilly, Jim Cavanaugh, and Marc Santia join Lawrence O'Donnell.

Lawmakers request more security after the Charlie Kirk killing. Also, NATO steps up its air defenses after Russian drones were shot down in Polish airspace. Plus, Donald Trump asks a federal appeals court to allow him to fire Lisa Cook ahead of Tuesday's Federal Reserve meeting. And consumer prices rose at an annual rate of 2.9 percent in August. Marc Santia, Michael Feinberg, Lt. Gen. Mark Hertling (ret.), Barbara McQuade, and Betsey Stevenson join Ali Velshi.