Holding vigil Saturday night outside the Tops supermarket where his 86-year-old mother was one of the 10 people murdered hours earlier , retired Buffalo Fire Commissioner Garnell W. Whitfield found light and joy in the life Ruth Whitfield lived. The African American mother of four had been shopping when she was shot by a white teenager who drove several hours here to commit what authorities believe was a racially motivated massacre. “I’m right across from Tops,” Whitfield told a reporter at about 9 p.m. in a phone call as he and other family members waited for more information. “I never dreamed I’d ever be having a phone call like this.” Though grief stricken, Whitfield wanted people to know what kind of woman his mother was.