MSNBC Dateline January 22, 2022 09:25:00
>> reporter: the defense contended the abuse was real, went on for years. and finally -- >> they came to believe that something terrible was about to break loose. >> reporter: specifically, that their parents were going to kill them if they didn't kill their parents first. mental health experts testified and said that was 'understandable.' >> erik and lyle menendez purchased the shotguns for their own protection. >> reporter: it was a high stakes defense. and by far the most important witnesses would be the brothers themselves. would the jury believe them? would america? coming up -- >> my dad...