Part 1- 17 year old identical twins David and Michael Samel rob and kill their friend, Bobby Sellon, in 1981. 

Part 2- Identical twins Jasmiyah and Tasmiyah Whitehead were 16 years old in 2010, when they stabbed their mother Nikki Whitehead, to death. 

For sources, visit: https://murderous-minors.podsite.io/episode/14-double-the-overkill-david-michael-samel-jasmiyah-tasmiyah-whitehead-301