i'm like, yo, that's paul dixon. i know him. >> estrada was surprised that dixon who has gone to jail numerous times before was so distressed. >> i'm not saying he's faking but sometimes you do stress out in here. some people are not built for this. >> he's going through some stress of his own. several weeks earlier he pled guilty to aggravated manslaughter for killing an 88-year-old world war ii veteran. he was described by his family as a vibrant and active great-grandfather. >> i don't want to go to hell for what happened. i'm really afraid. you know, i don't want to spend the rest of my eternity in hell. what happened was i was smoking angel dust and i ended up in one of my friend's grandfather's house. it was like, it gets you really paranoid and i went crazy and lost my mind. i went into the kitchen and i grabbed a pen to hit him twice or three times. the velocity of it was so fast, it was so hard that the pot itself was bent. it was bent in. i heard him yell, turned around and i started running and i remember t

paul? >> reporter: jenna, defense witness roger dixon on the stand again today thought to bring oscar pistorius's prosthetic leg to court but it took prosecutor gerrie nel seconds to expose that dixon left piece taken out of leg for tests, the actual evidence at home. now ridiculed him, asking why he would be testifying about evidence that was not in court? the prosecutor disputed just about every part of his testimony. one prosecution witness claims to have seen a man moving in "the blade runner"'s bathroom window at the time of the shooting. dixon present ad photo of a man on his knees to prove that pistorius on his stumps would have been too small to be scene but nel presented to the court that the act teeth on his stumps would be nearly eight inches or 20-centimeters taller and appears plainly visible. now a attacks dixon as he put it, misleading the court. >> we talked to an expert, mr. dixon. you're giving the court indication how much of the accused would have been visible. on his stumps, if he was on his stumps. then you give us a photograph that does not reflect that. why would you hand

paul? >> reporter: in the reconstructed toilet in court today to dispute the state pathologists view how reeva steinkamp received wounds on her back. when prosecutor gerrie nel came to cross-examination he tore into dixon coming to findings after looking at only photos and some reports. dixon was not at the autopsy, said nel. he wasn't a wounds ballistic expert or pathologist he has only been to three autopsies but stated that the state pathologist made mistake. once nel attacked he didn't let go. after dixon didn't use any instruments as decibel loudness meter on the defense sound tests. to find out how dark it was in "the blade runner" bedroom, dixon frankly astonished the court instruments he used were his eyes. >> all you did was you hit the cricket bat, the door with the bat? >> that is so, my lady. >> and with your visibility in the dark, you just used your own eyes? >> i used my eyes, my lady. >> reporter: nel piled it on regarding tests where a gun was fired saying dixon wasn't there for the test, the court documenter know where or how the tests was done, what recording was used but you say it was enough. nel found out music producer rather than a ballistics expert was used to record the gunsho