A 34-year-old man was fatally stabbed yesterday in Southeast Baltimore in what police believe was a domestic incident. Police were called about 12:30 a.m. to the 100 block of N. Janney St., east of Highlandtown near Eastern Avenue. An officer found Kenneth Ringgold of that address sitting on a sofa, suffering from a stab wound to the chest, police said. He was taken to an area hospital, where he died an hour later. Officer Troy Harris, a police spokesman, said police were interviewing a woman in connection with the slaying. Also last night, police were investigating the fatal shooting of man in the 600 block of N. Clinton St. Details were not available.