A gang member recently out of jail shot and killed a 9-year-old boy because he thought the child was warning his intended targets — rival gang members, Chicago Police Supt. Garry McCarthy said Friday. “This didn’t have to happen,” McCarthy told reporters as he announced charges in Antonio Smith’s murder.

The four men charged with first-degree murder are Derrick Allmon, 19, of the 7400 block of South Shore Drive; Jabari Williams, 22, of the 1900 block of North Sycamore Street in Hanover Park; Michael Baker, 19, of the 8100 block of South Wentworth Avenue; and Paris Denard, 19, of the 7300 block of South Dorchester Avenue.