Parents of Martin Richard argue against death penalty for Dzhokhar Tsarnaev . The 8-year-old boy was youngest of victims in the Boston Marathon bombings . Sentencing phase for Tsarnaev begins two years ago .
Parents of Martin Richard argue against death penalty for Dzhokhar Tsarnaev . The 8-year-old boy was youngest of victims in the Boston Marathon bombings . Sentencing phase for Tsarnaev begins next week .