A Texas district attorney said a convicted 79-year-old serial killer has been linked to over 60 killings in at least 14 different states, the Associated Press reports. Ector County District Attorney Bobby Bland reportedly said Friday that Samuel Little, who has drawn portraits of many of his victims while in prison, has been providing information to police about unsolved killings dating back to the 1970s. Bland said the killer was in bad health but was “determined to make sure that his victims are found.” Little is now serving a life sentence after he was convicted of three California killings and pleaded guilty to one in Texas. He reportedly claims to have killed at least 90 women as he lived a “nomadic lifestyle” over a number of years. The “Green River Killer,” also known as Gary Ridgway, is currently the most prolific serial killer in American history after he pleaded guilty to 48 murders—though he claimed that he killed 71 women and girls.