ST. PETERSBURG, Fla. (AP) — The FBI considers a 79-year-old California inmate to be the deadliest serial killer in U.S. history. Samuel Little told investigators last year he was responsible for about 90 killings nationwide between 1970 and 2005. Officials say analysts have been able to verify 50 of his confessions and they believe all of his admissions are credible. The FBI has provided dozens of color portraits Little drew in prison of some of his victims. They are haunting drawings, mostly of black women.