From Magic to Law: The Han Tak Lee Case and Arson Investigation
The Lee case teaches us that we must be diligent in researching and learning the science at every stage in the proceedings. We must consult with well-qualified experts in the field who are familiar with the existing scientific research and who are able to evaluate it and provide criticism where appropriate and we must thoroughly investigate the underpinnings of all expert testimony presented.“‘Slow and painful has been man's progress from magic to law.' This proverb, inscribed at the University of Pennsylvania Law School on the statue of Hseih-Chai, a mythological Chinese beast who was endowed with the faculty of discerning the guilty, is a fitting metaphor for both the progress of the law and the history of this case. The law is the means by which fragile, frail, imperfect persons and institutions seek greater perfection and justice through the search for the truth. But the search for the truth is not always easy, and the path to the truth is not always clear. Sometime we find that truth eludes us. Sometimes, with the benefit of insight gained over time, we learn that what was once regarded as truth is myth, and what was once accepted as science is superstition. So it is in this case.”
This is the opening paragraph of Magistrate Judge Carlson's findings and recommendation in the case Han Tak Lee.
The report by Judge Carlson describes in detail the legal odyssey of Han Tak Lee, a gentleman who was charged with the arson murder of his mentally ill daughter almost 25 years ago. The findings by Judge Carlson followed an evidentiary hearing ordered by the Third Circuit Court of Appeals in response to a Petition for Habeas Corpus filed by Mr. Lee arguing that the arson “science” evidence used to convict him was longer scientifically valid.
Specifically, the premise upon which much of “arson science” had been previously based that arson fires burn at much high temperatures and intensity than accidental fires has been thoroughly undermined. It is now well-understood that the temperature and intensity of a fire is determined by the amount of oxygen to which it is exposed. Additionally, the physical burn patterns such as alligator charring and crazed glass relied on by fire investigators as proof of arson, are now understood to be present in all types of fire. Fire investigators have also come to realize that flashover, a phenomenon previously regarded as rare, is commonplace in fires. Thus, much of what was once regarded as physical evidence of an intentionally set fire is now understood to be a consequence of all fires and by no means proof that a fire was intentionally set.
In Mr. Lee's case, two fire marshals testified unequivocally that the fire was intentionally set. One of the two experts testified that the cabin that was burned and in which the Mr. Lee's daughter died revealed burn patterns showing 8-9 places where fires were deliberately set using an accelerant. He testified further to the amount and possible types of accelerant used to set this fire despite the fact that chemical testing of those areas had not shown the presence of an accelerant.
There is an interesting footnote in the report regarding the testimony of this particular expert that he had been called upon to determine the cause of 15,000 fires over his career. The footnote reads: “This assertion gave Mr. Aston's expert opinion testimony a particularly compelling scientific cachet for a jury but, upon reflection, may be difficult to fully credit since in order to determine the cause of 15,000 fires Aston would have had to have averaged one fire cause determination per day for more than 41 years while working 7 days a week, and 365 days each year.” This provides a good reminder that information presented by expert witnesses should never be taken at face value, should always be scrutinized and investigated.
These two testified with great certainty that the fire was intentionally set and that Mr. Lee was the person who set the fire. The assertion that Mr. Lee was responsible for setting the fire was proved primarily through the testimony of a police chemist who had performed chemical testing on Mr. Lee's clothing and on a plastic water jug and glove found inside the cabin. This expert witness opined that the same accelerant was present on Mr. Lee's clothing and on the plastic water jug. However, at the time of this hearing, the gas chromatographs on which he had relied had gone missing and new tests performed on Mr. Lee's clothing called into question his opinion. According to the Magistrate Judge very little else established that the fire was intentionally set and that it was Mr. Lee who set it.
Strikingly the government conceded that the fire science presented at trial was no longer valid but argued that the conviction should nevertheless remain because the newly discovered evidence would only have been used to impeach the testimony of the experts and that the invalid scientific testimony did not “undermined the fundamental fairness of the entire trial because the probative value of [the fire expert] evidence, though relevant, is greatly outweighed by the prejudice to the accused from its admission.”
Despite the exacting standard Mr. Lee was required to meet, the Magistrate Judge found that Mr. Lee demonstrated that the admission of the fire expert testimony undermined the fundamental fairness of the entire trial and he was therefore entitled to relief. In recognition of the fact that justice requires courts to recognize that scientific truth often changes, he concludes “to achieve justice, the law must serve as the vehicle through which imperfect institutions strive for greater justice through a more perfect understanding of the truth. Therefore, as our understanding of scientific truth grows and changes, the law must follow the truth in order to secure justice.”
There are many lessons to be learned from this case going forward. What we know today about fire science is vastly different than what we knew 25 years ago. What we know today about many of the other forensic science disciplines including fingerprint and tool mark comparison evidence is presumably vastly different from what we will know in years from now as these scientific disciplines for the first time undergo validation. As noted by the Magistrate Judge “with the benefit of insight gained over time, we learn that what was once regarded as truth is myth, and what was once accepted as science is superstition.” The Lee case also teaches us that we must be diligent in researching and learning the science at every stage in the proceedings. We must consult with well-qualified experts in the field who are familiar with the existing scientific research and who are able to evaluate it and provide criticism where appropriate and we must thoroughly investigate the underpinnings of all expert testimony presented.