Saturday, May 12, 2012

Criminalistics: Science or Folkway?

Ahead of my May 8 talks to the forensics classes in the science department at Westwood High School in Round Rock, Texas, the teacher, Susan Seale, distributed a questionnaire of my own design.

Three intentions informed the instrument.  I wanted to prepare the classes to think about the science of crime scene investigation.  Second, how well could they correlate knowledge in general and about forensics especially. Also, I was fishing for an answer I did not have about the actual value of forensic psychology.

To take the last first: “In which cases did psychological profiling predict (or narrow the possible range) of the next victim and enable the capture of the criminal?”  The questionnaire (appended here), left this area blank. Any answer would do.  Of the 93 students, only one offered an answer not provided: “John Duffy (profiled by David Carter).” 

That sent me to the Internet. I discovered the case of John Duffy and David Mulcahy, the “Railway Killers” (or “Railway Rapists”), profiled by David Canter. (Dr. Canter’s website is here.)  In fact, Dr. David Canter only profiled Duffy. (“Much was made of the psychological profile constructed by Canter after the trial, as Duffy fitted 13 of the 17 observations made about the attacker's lifestyle and habits. Such profiling became immediately commonplace in policing thereafter.” – Wikipedia here.)   In fact, psychological profiling did nothing to capture George Metesky, John Duffy, or anyone else.  Psychological profiling is folkway masquerading as science. 

The students did a good job of identifying George Metesky, James Brussels, Fred Zain, and Joyce Gilchrist.  They also gave good summaries for the Daubert Test.  That said, though, they overwhelmingly believed that fingerprints, ballistics, and other perceptions are scientific.  In truth, only DNA meets the Daubert test.  

Kary Mullis received a Nobel Prize
for inventing PCR:polymerase chain reaction
which makes DNA typing cheap and reliable.
His website here.
It may well be true that a ballistics expert can match a bullet to a weapon. The methodology has never been statistically validated, or subjected to peer review, including the challenge of falsifiability. That holds true for fibers, hair, footprints, tire prints, or other evidence.  (Not only do you have have different kinds of hair all over your body - eyebrows, eyelashes, forearms, legs -  you have different kinds of hair on your head.) It may well be true that a perpetrator’s shoe can be matched to a print left at a crime scene.  But to what degree of matching? And how many other shoes would also match?  The reliability of fingerprinting remains the biggest lie in prosecutorial evidence.

I grant fully that I apply no scientific test to identify my wife. When I come home, I do not mistake her for a cousin of hers. Intuitive evidence is real.  But it is only evidence, not proof. And in a court of law, we demand more than gestalt feelings of lifelong familiarity.   

Now faith is the substance of things hoped for, the evidence of things not seen. Hebrews 11:1 ( Ἔστιν δὲ πίστις ἐλπιζομένων ὑπόστασις, πραγμάτων ἔλεγχος οὐ βλεπομένων.)

Tallies.  These are raw scores. I accepted most close answers. In some cases, the respondents missed the essence, for instance identifying correctly Joyce Gilchrist’s 3000 criminal cases and 20 years of service, but leaving out the charges of misconduct. Three caught my error in listing ”Fiber evidence” twice.

Take Home Survey
Prepared for Forensics classes at Westwood High School
By Michael E. Marotta, BS, MA.
May 8, 2012

Instructions: Do not put your name on this paper. It is an anonymous survey for statistical reporting.

Identify these:

George Metesky
92
James Brussels
91
Fred Zain
89
Joyce Gilchrist
77
Daubert Test
84


In which cases did psychological profiling predict (or narrow the possible range) of the next victim and enable the capture of the criminal?
George Metesky and/or James Brussels 75
Fred Zain 4
Joyce Gilchrist 15
Other Correct (Duffy/Canter; but others also generally correct) 9
Blank no answer 9 (No way to know if blanks indicate that the student believes psychological profiling to fail the Daubert Test. As Ellen Johnson famously noted: "The invisible and the non-existent look a lot alike.")
Other Incorrect 9

Which of these is an example of a scientific crime scene investigation method?
       Hypnosis          9
       Fingerprints      87
       DNA    87
       Hair Identification         87
       Fiber Identification        87
       Graphology 38
       Fiber Identification        (N/A)
       Shoe prints       80
       Tire prints         83
       Ballistics matching         83

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