Thousands of revelers roamed a dark street in a Florida town over the weekend, dressed in tattered clothing, their bodies daubed with fake blood and makeup that mimicked decaying flesh.

It was the annual Zombicon in Fort Myers, Fla., a night the organizers had advertised in good-natured fun as one when “the dead will once again rise.” But on Saturday, the street festival turned deadly when a shooting occurred.

One person was killed and five people were wounded. The sight of the injuries were at first confusing at an event packed with people in torn, bloodstained zombie costumes; some said they thought the shooting was part of the role-playing.

On Monday, the police were searching for the person or group that carried out the shooting. The mayor of Fort Myers, Randall P. Henderson Jr., said in a statement on Monday that the authorities were hoping that the suspects could be found through examination of video footage.