. >> a quiet family night at homeh shattered by intruders. >> the gun was like right here. >> a devoted father and husband dead. >> she just kept saying "they killed him." >> someone murdered her husband but left her alive, and that left police suspicious. was it possible she was involved in her husband's murder? >> the indicators are in cases like this that it's the spouse, not a random act. >> but why should she kill a man she obviously loved? >> they never fought. they always were very happy. >> this was a family affair all right. but it was another family that was keeping secrets. >> you ever see anything like that before? >> no. >> one father who fought to save his son. another who used his son to save himself. >> he's a monster. ♪ >>> hello and welcome to "dateline." joe morrissey was a respected scientist who loved his work. that's where he meto kay, who shared his passion and would eventually become h his second wife. then late one night joe, kay, andgh their young son were attacked insidewe their florida home. investigators did not know what to make of the strange circumstances

. >> a quiet family night at homeh shattered by intruders. >> the gun was like right here. >> a devotedad. >> she just kept saying "they killed him." >> someone murdered her husband but left her alive, and that left police suspicious. was it possible she was involved in her husband's murder? >> the indicators are in cases