dateline obtained a copy. it's never been broadcast before. in it, lyle wrote about their father, and the murders. "he bore two brilliant children only two, they carry his name and his pride. we did not do anything for the money." he went on -- "we alone know the truth. we alone know the secrets of our family's past. i do not look forward to broadcasting them around the country. i pray that it never has to happen. " secrets? at this point, even attorney leslie abramson knew, none of them. lyle and erik revealed nothing. not to abramson, and not to the forensic psychiatrist she hired, william vicary. >> what struck me in that initial interview was how together the older brother, lyle, was. i mean, he was articulate. he made good eye contact. he had very thoughtful, organized answers.