>> there's justice for my mom today. >> martin mcneill was sentenced to 17 years to life. e in full. in april 2017, martin died of soon side. a dark ending for the story of a family that began with so much hope. >> that is all for this edition of dateline. i'm craig melvin, thank you for watching! watching >> thank you for watching. i'm craig melvin. >> and i'm natalie morales. >> and this is "dateline." he's a monster. he's evil. he's pure evil. he is that character in those horror movies. >> he hid in the shadows. a killer in a mask. >> he's clearly a brilliant individual. a brilliantly scary individual. >> his target, a doting young mom. >> she was a gorgeous strawberry blond who loved her son more than anything in the whole world. >> she was so scared. >> he struck once. would he kill again and would she be next? >> we were just so shattered and hurting so bad.