A convicted serial killer and rapist who says he has murdered at least 100 women is expected to admit to the murders of five more victims after a DNA hit linked the killer to several unsolved crimes. Richard Cottingham, dubbed the “Torso Killer” for his tendency to dismember some of his victims, will reportedly plead guilty Monday to the 1968 murder of dance teacher Diane Cusick, along with the slayings of four other women on Long Island. Cusick was a mother who went out to buy dance shoes at the mall one day and never returned home. Sources told NewsDay that Cottingham will admit to 23-year-old Cusick’s strangling in return for immunity from prosecution in the other four killings. Cottingham is already spending life in prison after he was convicted of the murders of eight young women and girls but claims to have killed nearly 100 women across New Jersey and New York from the late 1960s to before his 1980 arrest.