A new book questions the science behind criminal investigations by examining a 27-year-old arson and murder case.
Jo Ann Parks’ Conviction
On April 9, 1989, the garage apartment of Jo Ann Parks went up in flames. Parks escaped, but her three young children were still inside. She ran next door to her neighbor’s house to call the police. Investigators initially believed that the fire was accidental, but eventually concluded that it was arson. Parks was accused of arson and the triple murder of her children.
At Parks’ trial, fire investigators testified that the fire was caused by human origin. One investigator testified that he believed that there had been two fires, one that was started in the living room and one that started in the children’s bedroom. Two points of origin meant that the fire was caused by arson because an accidental fire would only have one point of origin. Investigators also testified that they believed that one of the children had been trapped in a closet that had a door that was blocked by a laundry hamper.
Parks was convicted of first-degree murder and sentenced to life without the possibility of parole.
Humes’ Book
On January 8, 2019, Edward Humes published Burned: A Story of Murder and a Crime That Wasn’t. In his book, Humes recounts the story of the fire and its repercussions. Humes explains how on the night of the fire, Parks asked a police officer repeatedly if her children were okay and then complied with the request that she wait at a police station a few blocks away. Some of the jurors said that Parks’ acquiescence with that request without demanding to see her children was the deciding factor in their vote to convict her of arson.
Humes examined the way that evidence was collected in Parks’ case. Humes explained that the arson experts who testified at Parks’ trail relied on their mapping of the fire’s path. Humes explained that the arson experts did not fully understand flashover, which happens when a fire gets so hot that “every flammable surface in the room not already burning will ignite in rapid succession.”
To illustrate flashover, Humes explained an experiment that was conducted at the Federal Law Enforcement Training Center in Glynco, Georgia the same year that Parks’ trial took place. The experimenters set two rooms on fire and asked veteran arson investigators to examine each room and choose the quadrant of the room where the fire had started. While the participants thought that this would be an easy task, they chose the wrong quadrant more than 90 percent of the time. Humes explained that this and other similar experiments showed that flashovers made determining the cause of domestic fires very difficult. Despite the fact that flashover had occurred in Parks’ apartment, arson investigators testified that the burn patterns implicated Parks in the arson.
Humes notes that arson investigation is just one of many of the forensic techniques that have been recently discredited. He points to bite marks, hair and fiber comparisons, matching fingerprints, and lineups as examples of forensic investigation techniques that have been routinely discredited by later comparisons of DNA samples.
