In the wake of massacres like Wednesday's school shooting in Parkland, Fla., a small number of states have passed "red flag laws" that allow the seizure of guns before people can commit acts of violence.
California, Washington, Oregon, Indiana and Connecticut have statutes that can be used to temporarily take guns away from people whom a judge deems a threat to themselves or others. Lawmakers in 18 other states — including Florida — plus the District of Columbia have proposed similar measures.
Mental illness, escalating threats, substance abuse and domestic violence are among the circumstances under which a judge can order weapon restrictions.