jerry mitchell says they had good reason. in fact, the tree owe was delivered to a lynch mob by the county's deputy cher if, ce-- sheriff. it would take had 1 yeahs for a murder-- 21 years for a murder in the case. the master mained was this man. were you nervous? >> no. we're in a public place. it was going to be 9 o'clock at night and he was coming. >> reporter: his investigation helped secure new evidence leading to his conviction on three counts of manslaughter. mitchell grew up mostly on unaware of civil rights movement. >> i grew up in my insular kind of white south in east texas. i didn't get exposed to a lot of it. >> reporter: the movie mississipi burning opened his eyes. as did learning about his own newspaper's past. >> when you learn the legacy of this paper, what did you think? how did you feel? >> i was horrified >> reporter: decades earlier and under different earnship, it supported segregation and had close ties to the sovereignty commission, a state agency that kept tabs on activists like the three murdered m