said, and you have all the ingredients for a fatal confrontation. it got out of control, and michael peterson snapped. and he was the only one who could have done it, according to the prosecution. reporter: further evidence that michael attacked kathleen ferociously, the prosecution stated, was as clear as the spray of blood up the staircase walls. the amount of blood, the positioning of the blood, the location of the blood, it was overwhelming. in general terms, the greater the force, the smaller the drop. reporter: to take the jury vividly up the back stairs, the prosecution called the state s blood pattern expert, duane deaver. he told the jury with certainty that kathleen peterson had been beaten to death. he testified the droplet pattern high up the walls was just what you d expect to see with a weapon rising, striking, and casting off blood with each new blow. and i believe there is a minimum of four blows that have occurred in this, uh in this scene.
did duane deaver misrepresent himself to the jury? yes. did duane deaver s testimony make a difference in this case? yes. reporter: and there it was. michael peterson s conviction was tossed out. his family was overwhelmed. i was weeping with joy and shock and could not believe that there was hope. i was like, my dad s getting out. we re gonna have our dad back. reporter: for the peterson children, now there was only joy. lots of hugs. lots of happy, happy photographs. so we re all, like, jumping up into the air in a silly picture of just so so happy. reporter: twenty-four hours after the judge issued his decision sharply criticizing the blood pattern expert s work on the case, 68-year-old michael
those stairs. right, how long she d been actually been there. reporter: a blood pattern expert analyzed the scene. when he completed his initial findings, police suspicions were confirmed. he told me that he felt strongly that, um, this was a homicide. can you tell us how this has been for you and your family? reporter: just a few days before christmas, michael peterson was charged with the murder of his wife. they had the grand jury, and, of course, i was indicted. and so, i turned myself in. reporter: as the officers booked michael into the county jail, the blended family formed a unified block of support. my mother would just be absolutely appalled, and this is the last thing she would ever, ever want to happen to her husband. reporter: it was hardly the christmas that the peterson family had so looked forward to. kathleen dead, their father in jail. it was just us kids, you know, in that house by ourselves, you know, trying to piece together a christmas.
peterson had arranged to meet. we were to hook up. and what were you all planning on doing? having sex. reporter: the hookup never happened, but combine that with the other combustibles in the couple s life, the prosecution said, and you have all the ingredients for a fatal confrontation. it got out of control, and michael peterson snapped. and he was the only one who could have done it, according to the prosecution. reporter: further evidence that michael attacked kathleen ferociously, the prosecution stated, was as clear as the spray of blood up the staircase walls. the amount of blood, the positioning of the blood, the location of the blood, it was overwhelming. in general terms, the greater the force, the smaller the drop. reporter: to take the jury vividly up the back stairs, the prosecution called the state s blood pattern expert, duane deaver. he told the jury with certainty that kathleen peterson had been beaten to death. he testified the droplet pattern high
the back stairs, the prosecution called the state s blood pattern expert, duane deaver. he told the jury with certainty that kathleen peterson had been beaten to death. he testified the droplet pattern high up the walls was just what you d expect to see with a weapon rising, striking, and casting off blood with each new blow. and i believe there is a minimum of four blows that have occurred in this, uh in this scene. what s more, deaver testified, this blood stain was found on the inside of peterson s shorts. he d done tests that he says proved that the only way it could have gotten there was if peterson had been standing over his wife, beating her. and the individual wearing these pants at time of that impact was in close proximity to the source of blood when it was impacted. i remember the jurors were captivated by his testimony. um, and it all seemed to make perfect sense. then there was all that dried blood the emts noticed around