Samantha Koenig was kidnapped at gunpoint from the Anchorage, Alaska, coffee stand where she worked as a barista in February 2013 by a man who may be one of the most prolific serial killer in U.S. history. Israel Keyes developed an elaborate plan to demand a ransom for the 18-year-old's return. 

After his arrest, Keyes  admits to killing 11 people across the country, but are there more?