Officials clearly feared a repeat of the past summer’s protests, which gave way to violent demonstrations and deadly acts of vigilantism. On the second night, Rittenhouse, a teenager from suburban Chicago who had volunteered to protect a local business from vandalism, fatally shot protesters Joseph Rosenbaum, 36, and Anthony Huber, 26, and wounded Gaige Grosskreutz, who prosecutors have said was armed with a handgun.