investigators say the killer was christopher lee robinson, her ex-boyfriend, who took his own life after the shooting. hartman, the mother of a 6-year- old, leaves behind a devastated family. >> we want to know why, why this happened. >> reporter: hoffman has been hailed a hero, awarded the chief thomas medal of courage in 2010 for rescuing a man from a fire on gillman street. and this year, recognized by wjz, helping to save this 3- year-old boy who had wandered away from home. friends say the third generation firefighter was heroic, even in his 90 final minutes. >> the night he was killed, he did all he could to protect his girlfriend and her sister, who survived the terrible ordeal. and i think without andy's help, that would not have been possible. >> reporter: wjz was there, as his uncle collected some items from andrew's home, needed for funeral arrangements. his father released a written statement, on behalf of his family, saying our hearts are absolutely broken over the loss of our son, brother, grandson and uncle. it's hard to imagine going forward without him. but we know andy