How a Texas ranger helped solve 50 cold cases
The FBI now describes Samuel Little as the most prolific serial killer in U.S. history, after he confessed to murdering 93 people. Little was sentenced to three life terms in 2014 for killing three women. Now, investigators are asking the public to help identify his other victims. "60 Minutes" spoke to Little and the Texas ranger who got him to tell his stories, using a sketch pad. Jericka Duncan reports.