Chicago officials have charged two female cousins in a six week string of killings that left four people dead on the city's South Side. Police say the 26-year-old cousins killed three men in a series of "prostitution-related robberies." They also say the women shot an acquaintance to death during an argument Thursday. Each victim was shot in the back of the head. Angela Wright and Caroline Peoples are both charged with four counts of first-degree murder and four counts of armed robbery.