This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.MEMPHIS, Tenn. — Memphis police confirm the fourth suspect arrested for the murder of 7-year-old Kirsten Williams is the brother of a teenager who was killed hours before, according to court records. Police are not confirming the incidents are related. Carlos Stokes, 22, was arrested Wednesday night on first degree murder charges. According to Shelby County court documents, Carlos Stokes lives at 4581 Cottonwood. Cateria Stokes, 15, was shot and killed just before 2:00 a.m. on April 10 while sleeping in her bed in a home at 4581 Cottonwood. A 61-year-old man who was also shot there is recovering. The night before Cateria was shot, a 22-year-old man was shot at a home on Durby Circle which is about five miles from Cottonwood. The next afternoon 7-year-old Kirsten Williams was shot and killed while she played outside a home also on Durby Circle. According to an affidavit, one of Carlos Stokes’ co-defendants identified him as the person who planned that shooting, in retaliation for the shooting of the 22-year-old. Police say the shooting of the 22-year-old was drug and gang related. Carl Johnson, 19, Jordan Clayton, 21, and Branden Brookins, 19, are also charged with first-degree murder for the killing of Kirsten Williams.