Far too late to save the life of Trayvon Martin, the community of Sanford, Fla., where Mr. Martin was shot to death last year by a roaming neighborhood watch volunteer, is wisely changing course and banning civilians from packing firearms on future citizen patrols.

The lethal folly of allowing armed volunteers to strut about, largely unsupervised, in the name of neighborhood protection was laid bare in the tragic death of Mr. Martin, an unarmed teenager who was walking home from a store errand. George Zimmerman, a watch volunteer who decided the teenager was a suspicious presence in the neighborhood, ignored a telephoned caution from the police and tracked Mr. Martin to the point of a deadly confrontation. Mr. Zimmerman was eventually found not guilty of second degree murder. He and his attorneys had argued that Mr. Martin tried to seize his handgun and was fatally shot in a struggle.

In the wake of national outrage, the Sanford police have announced a plan to take far greater control of neighborhood watch programs. Clear training requirements will be introduced along with a no-guns mandate. Floridians will be well served. “We just don’t see the need for anybody to be armed,” the police chief, Cecil Smith, explained.

Florida’s laissez-faire gun culture is epitomized by the state’s Stand Your Ground law. It, unlike traditional doctrine requiring a citizen to retreat from danger, gives a legally armed person dangerous leeway to decide when he feels threatened enough to use a firearm. So much confusion and vigilante violence has ensued that the Florida Legislature — traditionally fertile ground for the National Rifle Association — is considering proposals to rein in the law. No one is promising success, but at least the second thoughts in Sanford will make that community safer.