As KRON4 is telling us, a 62-year-old homeless woman named Fafa Chan, who police recognized at a bus stop after seeing her starting a fire on a surveillance video, is the prime carsonist suspect in that string of auto fires last month, and also in that string of porta-potty blazes this past winter. Both strings of fires were centered around the Russian Hill vicinity, where Fafa likes to hang, but so far police haven't put together much evidence of Fafa's guilt besides the fact that the fires stopped as soon as they had her in custody. Obviously she isn't much of a talker.