. >> reporter: as for deborah viagas, the defense attorney prize e surprised everyone when he didn't question. but he asked calleb how long he sat on that story. >> you didn't tell your mother when you first heard about that. >> no. i didn't see relevance. >> when you spent time with him, things were good? >> yes. >> okay. you love your dad? >> yes. >> reporter: would jurors notice the tear rolling down tony's cheek? on to the scientific evidence, the cell phone first. lawyer fletcher found a mistake in the chart that was used. was the expert analysis sloppy? >> if you're a hot-shot expert, how does this error creep in. >> it was a mistake. >> reporter: the same went for the dna evidence. attack the credibility of the analysis. the defense said the dna results returned within a few days were rushed with the police lab was a of rothstein's connections. attorney fletcher suggested there could have been cross-contamination to tip the scale. >> our goal was to educate the jury on the rothstein connections and the rothstein influence. >> reporter: had meddled with the physical evidence. c