This undated photo obtained November 28, 2018, courtesy of Ector County Sheriff’s Office shows convicted serial killer Samuel Little. – A 78-year-old drifter in prison in Texas has confessed to 90 murders and is being investigated as possibly the most prolific serial killer in US history. Samuel Little preyed mainly on drug addicts and prostitutes during a decades-long murder spree that stretched from coast-to-coast, according to the FBI. Little, a 6ft 3in (1.9m) former boxer also known as Samuel McDowell, was arrested at a homeless shelter in Kentucky in 2012 and extradited to California to face drug charges. Once there, DNA evidence linked him to three cold case murders and Little was convicted in 2014 of murdering three women between 1987 and 1989.All three women had been beaten and strangled.Sentenced to life in prison, Little was transferred to Texas in connection with the investigation into another murder. (Photo by HO / Ector County Sheriff’s Office / AFP) / RESTRICTED TO EDITORIAL USE – MANDATORY CREDIT “AFP PHOTO / ECTOR COUNTY SHERIFF’S OFFICE” – NO MARKETING NO ADVERTISING CAMPAIGNS – DISTRIBUTED AS A SERVICE TO CLIENTS