The forensic sciences, as a form of professional knowledge, are changing with new advancements in technology and continuing research and development. With the National Academy of Science's recent call for more research and testing of the forensic sciences, the criminal justice system is faced with the challenges of handling cases where convictions are based on outdated or discredited evidence. In light of technological advancements in the field, this article examines the evolution of fire- and arson-investigation knowledge over the course of a highly publicized capital murder case. The history of arson investigation is discussed, as is the legal admissibility of such expert testimony. Arson investigation expertise stems from non-scientific or experience-based origins, yet is conveyed in court as scientific fact. The article identifies the dangers of admitting such testimony into court without scrutiny. The lack of scientific validation of investigative methods, overreaching scientific claims based on case facts and witness statements, and fire investigators' susceptibility to contextual bias are discussed. The article raises questions as to whether and how the legal system has propagated the misuse of arson investigation testimony and how outdated understandings of evidence may impact the identification of future miscarriages of justice.