Only on the "CBS This Morning" podcast, CTM national correspondent Jericka Duncan talks with Philadelphia District Attorney Larry Krasner about the work he has done to reform the criminal justice system in his city. Krasner has been on the job for less than two years and explains why he has made it his mission to reverse unjust sentences and change the way crimes are handled in the city's courts. Plus he shares details on how he and his team have been able to exonerate nine people in the last 19 months.