. >> who is joseph holt. >> joseph holt was lincoln's judge advocate general. and if people remember him today, they'd particularly remember him as the judge advocate general who was after lincoln's assassination was in charge of prosecuting the conspirators who had worked with john will can's booth. however,ees much larger figure than that. he was 50-some years old by the time he got to washington and by the time he became lincoln's judge advocate general and he had a very long life and he lived on to 1894. so he's a much bigger figure than that. the way we know him for years as lincoln's judge advocate general. >> you've titled "lincoln's forgotten ally." why did you choose this as a title? >> because of his importance to lincoln. because of his deep devotion to lincoln and his policies and, therefore, he is lincoln's ally, but he is someone whom we simply don't remember in the historical record except in terms of a tiny slice of what role he played over the course of his life as a professional. so he was to me one of the most important members of lincoln's a

. >> who is joseph holt?ncoln's judge advocate general and if people remember him today, they particularly remember him as the judge advocate general who was after lincoln's assassination responsible for prosecuting the conspirators who had worked with john wilkes-booth. however, he is a much larger figure than that. he had a very -- he was 50 some years old by the time he got to washington and by the time he became lincoln's judge advocate general. he had a very long life and he lived on 21894 so he is a much bigger figure than that but the way we know him best is as judge advocate general. >> you titled this, "lincoln's forgotten ally." why did you choose this as a tidal? >> because it was important to lincoln. because of his deep devotion to lincoln and his policies and therefore he is lincoln's ally. but he is someone who we simply don't remember in historical records except in terms of a tiny slice of what role he played over the course of his life. as a professional. so, he was to me one of the most imp

holt heard about it, he knew he had to call the boy's grandfather. joe walker had been raising him. >> i had a chance to talk with his grandfather, joseph walker, and heked up the phone. he said brother holt, i was waiting for you to call me. i said let's talk because i know you want to talk about it, i know you're angry, i know you're bitter, and then the flood gates just opened. >> he was sitting at this desk the night before he got killed. he was sitting right here. >> what was he doing? >> on his computer. that was the last conversation we had other than leaving the house that morning. >> i went through the same thing with the night before. birth to death. reality we have to deal with now. >> he can pick through old photos of his grandson, but he cannot bring himself to look at the last image of darrien. >> you have not seen that video? >> never in my life, never. >> but you know what's on it? >> it woke up the world. my grandson's death woke up the world, woke up a nation. people saw that video and was mad. they were mad. >> it's time for it to end. we cannot allow our young people to continue to be killed. >> in fact, his death didn't just gallo