>> yes. >> prosecutor lisa pell agree niece at the defended thought he was so smart.by using a poisoned, he assumed, was untraceable. >> standing and looking at the jury. points to ferrante. that man, right there was one blood tests away from the perfect murder. >> murder responded the defense? what murder. >> robert ferrante, had said he did not commit a crime. because there was no crime. >> i said this forcefully as i could. we don't believe and we will never believe that autumn klein died from cyanide. >> the defense was attacking the cornerstone of the commonwealth case, that looked at with the little reading of cyanide could never be trusted, it's. it >> there is no way that that result is -- >> thrown up? >> yes. >> because, he said, the lab initially screwed up with the three point 35 calculation. it only caught its air months later. correcting the level to 2.2. a still, lethal amount of cyanide in autumn's blood. >> it certainly raises a real issue of credibility. >> it gives the defense something to work with. >> it absolutely gave the defense a lot to work.