Red flag laws: What are they and do they work?

The President is proposing Red Flag laws in response to a weekend of mass killings. Colorado's version is so new it hasn't even gone into effect. Other states are trying it, too. But what are they? And do they work?
Published: 10:27 PM MDT August 5, 2019
Updated: 10:26 PM MDT August 5, 2019