Lawmakers reacted to the Santa Barbara shooting by announcing plans Tuesday for a bill to create a “gun violence restraining order.” The bill would establish a system in which concerned relatives, intimate partners or friends can notify police about someone showing a propensity toward violence, so police can investigate and seek a judge’s order to seize that person’s firearms and prevent any purchases. Current law lets that process start only when therapists notify police that a client is at risk of committing a violent...