Thursday, February 9, 2012

Fatal Vision and Myopic Views

I just looked at the date on my last post and saw that it was in January.  Time just races by when school is in session!  Two other teachers and I have been working on the curriculum for a new course in our science department: forensics. Maybe I'm only now getting into the swing of things, but it seems that the units we've been covering this semester have been more interesting.  And I think it's not just my perception; some students told me they really enjoyed our unit on blood spatter.  If you can get past the cause of the spatter, it's really intriguing how much information can be gleaned from observing the pattern and the size of the drops.  I even had to reach back into my cobwebby past to remember how to find the degrees of an angle when the sine is known.  Of course, these days one can just push a few buttons on a graphing or scientific calculator and find the inverse sine.  Back when I took trig, we had to look up the information in endless tables in the back of our book.  I definitely agree with the song, "....these ARE the good old days"!


In the course of our unit on blood (typing and spatter), we looked at two very different cases: the Sam Sheppard case and the Jeffrey MacDonald trial.  In both cases, the men eventually charged with the murders of their wives (and family, in the MacDonald one) were young, medical doctors who claimed they were sleeping when intruders invaded their home.  In the Sheppard case, the pre-trial publicity was so intense, the Supreme Court later over-turned the conviction because of the prejudicial nature of it.  Charges were brought a second time, but after having served 10 years in jail, Sam Sheppard was acquitted at that trial.  He didn't live very long, and found life quite difficult because people would still accost him in the street and taunt him by calling him wife-killer.  He turned to drugs, alcohol, and professional wrestling (!) and died at the age of 46.  The 1960s television show, The Fugitive, was based on his case.


In the MacDonald case, the husband was not initially charged, but after tireless investigative work, his former father-in-law managed to convince the DA in North Carolina that a grand jury should be called.  MacDonald was convicted almost 10 years after the murders and is now serving three consecutive life sentences.  He will be eligible for parole in May of 2020, continues to maintain his innocence, and  holds the record for appeals to the Supreme Court for a single case.  The forensic evidence in the MacDonald case is overwhelming on the side of MacDonald's guilt (each family member had a different blood type, and a strong case was made for the sequence of events told by the blood trail and spatters).  Because the Marilyn Sheppard murder occurred in 1954, only a year after the publication of the structure of DNA, the evidence wasn't handled and preserved in a way that could settle beyond doubt the guilt or innocence of Sam Sheppard.  But unlike Jeffrey MacDonald, who suffered comparatively superficial injuries, Sam Sheppard had a broken vertebra in his neck, consistent with his story that someone had struck him from behind as he raced to aide his wife.


As we studied these cases, I thought of how easy it can be to race to judgment on limited evidence.  And I also thought of the lives ruined because of this (Sam Sheppard's mother committed suicide days after he began his prison term, and his father died a few days later of a stroke).  Not only is it a cautionary tale against leaping to conclusions, but it is a motivator to be diligent in our efforts to bring the best science has to offer to insure that justice is served.  It is so absolutely amazing what small amounts of DNA can be detected at crime scenes that it is my fervent hope that miscarriages of justice will become vanishingly rare.  And I also hope, after being in my forensics class, that any of my students who become jurors, prosecutors, defense attorneys, or heaven forbid, defendants will remember those two men and understand what a decisive role forensic evidence (and the correct interpretation of it) can play.  And be grateful.