-- Boston police arrested a woman for setting the fire that killed two young girls, Acia Johnson, 14, and her 3-year-old sister, Sophia, in South Boston last month. Nicole Chuminski, 25, will be arraigned Monday on two counts of murder and one count of arson. Chuminski was reportedly the girlfriend of the victims' mother, and the alleged arson may have been the outcome of a vicious spat. [Globe; Herald] -- The truck driver whose careering......