Two teenaged girls have been charged with murder after the charred remains of their mother and brother were discovered from their residence in Darbhanga early on Thursday morning. Police said Sumitra Devi,a 42-year-old clerk with the Public Health and Engineering Department (PHED),and her son Mukesh Kumar,a 22-year-old biotechnology student at Raigarh in UP,were found charred to death. Devis daughters Madhu (19) and Mala (16) later confessed to the crime saying their brother used to harass them.