that could be trusted. >> the blood in that area had been completely altered. the scene at the house had been completely contaminated. >> reporter: but what about those ghastly lacerations on kathleen's head which the state's medical examiner attributed to a beating? defense attorney rudolf notes what he didn't find -- though the cuts were deep, there were no skull or bone fractures. >> there was absolutely no fractures anywhere no fractures to her fingers, to her arms to her skull. and there was absolutely no injury to the brain. and that's just almost an impossibility if what you're doing is beating somebody with a metal object >> reporter: and for a final exclamation point, the defense had a "perry mason" moment up its sleeve the prosecution had insisted throughout the murder weapon used to bludgeon kathleen peterson was the fireplace blowpoke, only police never found it