Only on the "CBS This Morning" podcast, director and producer Erin Lee Carr joins CBS News' Meg Oliver to discuss her new, two-part HBO documentary about the case against Michelle Carter, the teenage girl who sent text messages encouraging her boyfriend, Conrad Roy, to take his own life in 2014. "I Love You, Now Die: The Commonwealth V. Michelle Carter" explores the couple?s mental health and how technology can amplify teenagers' problems. Carr explains what she learned from reading logs of both teenagers' text messages and the factors that contributed to this tragedy. A lawyer for Michelle Carter did not respond to a request for comment.