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On December 9th, 2001 in Durham, North Carolina, Kathleen Peterson died. According to the 911 call, she was found by her husband Michael Peterson at the bottom of a staircase in their home. He was soon charged with first degree murder, that it had not been a fall, but he had in fact beaten her to death. He was found guilty at trial, and sentenced to life in prison. Eight years later, he was granted a new trial.

A deciding factor for the guilty verdict from the jury was a bloodstain found inside Mr. Peterson’s shorts. It was eventually found out that the prosecution’s Blood Spatter Analyst, Duane Deaver, was reporting false information, withholding information, and being inattentive in, not only Mr. Peterson’s case, but numerous other cases.

During the trial, the district attorney, Jim Hardin, made the case Kathleen had been beaten to death at the bottom of the stairs by Michael due to the large quantity of blood and the injuries to her head. She had seven tears of the scalp but no skull fractures, no brain swelling, and no bruising of the brain. They believed the seven lacerations must be from a beating by a weapon such as a blow poke, a brass fireplace tool, because it could cause lacerations yet it is hollow so it would not cause further damage. Deaver came to the conclusion that there had to be at least four blows to Kathleen’s head to cause the spatter on the wall. In an experiment, Deaver placed a bloody sponge in the staircase that represented Kathleen’s head and showed the jury he was able to get blood on the inside of his shorts, like Michael’s. Since there was no cast-off blood pattern, he proposed the weapon had been cleaned in between strikes.

The defense team included defense attorney David Rudolf, Dr. Werner Spitz, a Forensic Pathologist, Dr. Faris Bandak, an Injury Biomechanics Expert, Dr. Henry Lee, a Forensic Scientist, Tim Palmbach, a DNA Expert, and Ron Guerette, a Private Investigator. Collectively, they proposed the idea Kathleen tripped walking up the staircase, fell backwards and hit her head on the door frame, causing the larger lacerations and a lot of blood to be drawn. She likely knocked herself out then tried to stand upon waking, but was dizzy and slipped on her blood and fell again causing the other lacerations. She likely had a lot of blood on her face, in her hair and if she was coughing, it would have produced a bloodstain pattern on the wall.

After the guilty verdict, Mr. Peterson spent eight years of his life sentence in prison before some key issues regarding his trial came to light. One piece of key evidence that was overlooked was Michael’s navy blue shirt. Deaver said bloodstain pattern analysis is a “visual examination” and since he did not see blood on the shirt it was not tested. In reality, not all blood spatter can be seen with the naked eye. There are other methods to enhance one’s ability to see blood such as chemical techniques or alternative light sources. Deaver eventually admitted that he did do a Luma-Light test on Michael’s shirt and did not find blood spatter, supporting the defense. This information was withheld from the defense team and came out during the trial.

Another problem was with Deaver’s experiment mentioned above; he lifted his leg and pulled his shorts leg open before beating the sponge with an object that resembled a blow poke, a guaranteed way to get blood in the shorts and match the evidence. The sponge was also moved to a location in the staircase that could be struck more easily by a blow poke than in the location Deaver calculated Kathleen’s head was allegedly hit.

Furthermore, the instructions from the police department were to do DNA testing on Michael and Kathleen’s clothing before bloodstain analysis. Susie Baker, who worked with Deaver, changed the instructions to have the clothing sent straight to Deaver for bloodstain analysis. The evidence was never tested for DNA and was not stored properly.

The issues with the compromised forensic evidence gave the defense team enough leverage to come to a plea agreement with the new district attorney in 2017, that Peterson would take and Alford Plea in order to avoid a new trial. An Alford plea means that the defendant does not admit to guilt, but acknowledges that the state either has enough evidence to convict, or in Peterson’s case, he simply did not want to go through the ordeal of a new trial, when he felt the system had failed him once and may do so again. He was sentenced to time served. The judge in the case later acknowledged that he felt a second trial would have left reasonable doubt not to convict.

The Peterson case is the subject of the popular documentary series on Netflix The Staircase.

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