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john lewin. >> lewin feared because of durst's resources some of these witnesses might get whacked. >favor for durst. >> she said i did something today and i did it for bobby and if anything ever happens, bobby did it. >> reporter: the star witness for the prosecution was nick chafin accompanied by a s.w.a.t. team for protection. he was close to both susan and robert. >> they were my two best friends which is a very strange position. >> reporter: more than a decade after berman had been killed, durst asked chafin to dinner and told him he wanted to talk about their friend. chafin keeping durst's secret for more than two years until he was finally convinced to talk by the district attorney. >> honestly ask yourself is bob worth it? >> so nick recounts to lewin exactly what happened. >> bob said, i had to. it was her or me. i had no choice. >> so it's a very dramatic moment. llighteveryo devil you know" airs tonight at 9:00 eastern right here on abc and if you can't do it tonight, well, you got tomorrow on hulu, guys. >> we'll certainly be watching, thanks, amy. >>> let's head over to g