Jessica Kensky & Patrick Downes

One killer is dead, another slated for execution, and the wounds the Tsarnaev brothers inflicted that terrible day in 2013 may never heal completely.

Their crime — setting off two bombs near the Boston Marathon finish line, killing three people and wounding hundreds — forms the dark stage upon which HBO’s new documentary, “Marathon: The Patriots Day Bombing,” tells its nuanced story of redemption. CLICK FOR MORE