Little reportedly told officers that he was a good drawer and promised last year to produce portraits of his victims from memory.
He used a combination of chalk, pastel pencils and water colours to capture the faces of 16 of the women in their final moments.
Bernie Nelson, a detective looking into one of the unsolved cases, told the Washington Post: “Talking with him, you can hear he actually gets excited about describing his homicides and describing how he strangled his victims,”