GREENSBORO — The new year started on a deadly note, with an aggravated assault in Greensboro that left three people dead — two of them children. Police identified the victims in the triple slaying as 61-year-old Jerry Griffin, 10-year-old Mkenzie Denise McKinney and 2-year-old Serenity Taliem Rose. All three were shot, according to Ron Glenn, a spokesman for the police department. Brittany Christina McKinney, 28, of Greensboro is charged with three counts of first-degree murder in the deaths, police said in a news release. She is scheduled to appear in court Thursday afternoon. Officers responded about 11:15 a.m. Wednesday to a welfare check in the 3600 block of Sweet Birch Drive in southeast Greensboro. A relative had contacted police to request the check, Glenn said. Two victims were found dead at the scene, Glenn said, and a third victim was taken to a hospital, where that victim later died. Glenn would not say which victim was taken to the hospital. McKinney is a relati