Over the next three days, the Casey Anthony case will take a scientific detour, the primary purpose of which is for Judge Perry to decide whether to admit testimony from Dr. Arpad Vass regarding his decompositional odor analysis of Casey Anthony’s trunk, an analysis that supposedly revealed the presence of Chloroform – a compound alleged by Dr. Vass to be unique to decomposing bodies.
Who is Dr. Arpad Vass?
Dr. Arpad Vass is a “research chemist scientist and forensic anthropologist based at the Life Sciences Division of Oak Ridge National Laboratory.”
What is Decompositional odor analysis?
According to Dr. Vass, deceased human beings release volatile chemical compounds during the decompositional process. Dr. Vass claims these compounds are the same “odors” that cadaver dogs detect when searching for human remains.
As a result of this hypothesis, Dr. Vass (in conjunction with the FBI) has compiled a “Decompositional Odor Analysis Database” consisting of over 478 compounds that are released by decomposing bodies.
The development of this database is outlined in several of his research papers:
- Decompositional Odor Analysis Database
- Odor analysis of decomposing buried human remains
It is important to understand that the only person that knows all of the compounds in the database is Dr. Vass (and presumably the FBI), thus making it a proprietary database.
Why is the Defense Objecting to Dr. Vass’ Testimony
The Casey Anthony defense team is objecting to Dr. Vass’ testimony on the basis that it is based on “new or novel scientific techniques.” As a result, the defense has convinced Judge Perry to hold a Frye hearing to require the State to prove that Dr. Vass’ testimony is not based on new or novel scientific techniques.
What is a Frye Hearing?
A Frye hearing gets its name from Frye v. United States, 293 F. 1013 (D.C. Cir. 1923), which held that before new or novel scientific techniques will be admissible, the court must find that the “scientific principles and methodologies” which the expert relies upon in rendering the opinion are generally accepted within the scientific community.
What is Generally Accepted within the Scientific Community mean?
Essentially, to be generally accepted within the scientific community, the methods and principles you relied upon in reaching your opinion must be generally accepted to be true and by your peers.
It is important to note that your peers do not have to agree with the opinion you reached, just agree that the methods and principles you relied upon in reaching your conclusion are generally accepted.
An excellent example of this occurred when the defense tried to exclude Dr. David Hall’s testimony in the field of botany. Judge Perry astutely pointed out that his testimony was purely opinion that was based upon general principles within the botany community.
How is Dr. Vass’ Testimony Different from Dr. Hall’s?
It may very well be that Judge Perry rules that Dr. Vass’ testimony is purely opinion testimony based on generally accepted “scientific principles and methodologies.”
However, Dr. Vass’ testimony differs from Dr. Hall in one major respect; Dr. Vass’ testimony is based upon a proprietary database that he developed through his own research.
The Heart of the Defense Argument
If you read Dr. Vass’ report in the Casey Athony case, it essentially requires the reader to take his word that the compounds he identified in Casey Anthony’s trunk suggest a “decompositional event” because they match the compounds in his database – a database of 478 compounds that are a mystery to everyone but him.
However, Dr. Vass’ research seems to have been developed for commercial and governmental purposes, as Dr. Vass has obtained a patent for a “Clandestine Grave Detector,” which is based on his research. Additionally, the FBI is part owner of the “Decompositional Odor Analysis Database” because they funded his research.
This commercial motive is important because Dr. Vass has a vested interest in his research being validated by utilizing his research on behalf of the State at the Casey Anthony trial.
This validation would stand in stark contrast to his 2008 work in the Charles Manson case where he attempted to use his research to identify “clandestine graves” at the infamous Barker Ranch. According to Dr. Vass, his research is so accurate that he can’t differentiate whether the decompositional event was from “an animal, Native American, or a dinosaur.”
Needless to say, they did not find any bodies on the Barker Ranch to validate Dr. Vass’ claims that a decompositional event took place; which begs the question, how do we know his conclusions were correct?
This is the same question that we must ask in the Casey Anthony case. If nobody but Dr. Vass has access to his database, how can anybody in the scientific community determine if the methods and principles he relied upon in compiling the database were generally accepted?
And if we can’t determine if his methods and principles were generally accepted, how can we let him testify to something that only he would know the answer to.
Another Problem of Dr. Vass’ Research
If you read Dr. Vass’ literature, he appears fixated on the issue of Fluorinated water – essentially believing that because we fluorinate our water, this compound is usually present in decompositional events.
However, fluoride was not present in his report in the Casey Anthony case. Instead, he accounts for the absence of fluoride to Caylee’s young age; meaning she did not live long enough to absorb the fluorine into her bones.
But the question must be asked, what basis does he have to dismiss the presence of fluoride? If his work has not been sufficiently peer reviewed, how can we know that the methods and principles he relied upon in reaching that conclusion are scientifically accepted?
From a statistical point of view, he has developed his database on a relatively small number of cadavers (according to his first paper, only four cadavers were used). Any statistician will tell you that you need at least 200 samples before you can make a statistically reliable conclusion. So it is difficult to believe that his reliance on such a small statistical sample would be accepted by peers in the scientific community.
Peer Review, Schmear Review
Essentially Dr. Vass has created a secret database that has not been peer-reviewed and cannot be peer reviewed – which is the hallmark of trusted scientific evidence.
(Yes, ValHall at the Hinky Meter did an excellent review of much of the science behind Dr. Vass’ work last year. While ValHal was of the opinion that his research was peer-reviewed, I respectfully disagree.)
Because any peer review of Dr. Vass’ research would by definition be incomplete unless the reviewer had complete access to his decompositional odor database. Without access to this database, it is impossible to thoroughly peer review his research.
And peer review is the hallmark for determining whether a principle or methodology is generally accepted within the scientific community.
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