In the United States, criminal convictions require that the jurors have no reasonable
doubts about the suspect’s guilt. If there are any,
the jurors must vote not guilty. In the eyes of the law, guilt beyond a reasonable
doubt is the highest standard of justification, used primarily to ensure that
innocent people are not wrongly convicted. But jurors (and even legal experts)
often have different conceptions of reasonable doubt. Can a reasonable doubt be
quantified in probabilistic terms (e.g. 5% chance suspect is innocent)? Can a
reasonable doubt be determined by self-reports of confidence? How do you determine
whether a judgment is reasonable? Reasonable given the jurors’ background
knowledge and cognitive abilities? Or is there some way of determining whether
a judgment is reasonable without taking into account of knowledge and
intelligence?
To further analyze this concept of reasonable doubt, it helps
to apply it to a real-world case: The OJ Simpson trial (see Toobin 2015 for a detailed account of the events).
There are at least three distinct questions that are often conflated
about the OJ verdict:
1)
Did OJ commit the murders?
2)
Is it reasonable to doubt that OJ committed the
murders?
3)
Did the prosecution’s
evidence prove beyond a reasonable doubt that OJ committed the murders?
While there may be a consensus among legal experts regarding the first two
questions, some prominent legal experts disagree about the third. Did the jury reach
the proper verdict?*
Harvard Law Professor Alan Dershowitz, who was part of Simpson’s
defense team, argues that given the evidence presented, the jury was reasonable
to believe that the LAPD lied and fabricated some of the evidence (Dershowitz, 1996). These beliefs were reasonable because the defense team presented
the jury with information about a chemical compound EDTA that was found in the
blood sample taken from OJ’s sock. The defense team argued that the presence of
EDTA indicated that the blood did not come directly from Simpson, but came from
a preserved sample of his blood taken by the LAPD detectives. One of the theories presented to the jury was that one of the officers spilled the blood obtained from Simpson on
the sock so that they would have conclusive evidence of his guilt. Dershowitz
then argues that if the LAPD fabricated some evidence, it is reasonable to
conclude that the prosecution did not prove beyond a reasonable doubt that OJ
was guilty. To
support this conclusion, Dershowtiz cites a closing argument by one of his
expert witnesses, Dr. Henry Lee: "If you find a cockroach in a bowl of
spaghetti, you don't look for another cockroach before you throw out the whole
bowl of spaghetti."
Former prosecutor Vincent Bugliosi disagrees with Dershowitz’s
analysis of the verdict. Bugliosi argues that, even if it was reasonable to believe
that some of the evidence was fabricated,
it was still unreasonable to doubt Simpson committed the murders, given that
there was still ample evidence of his guilt. These opposing viewpoints held by two
prominent legal experts raises an interesting question about the reasonable
doubt standard: how much evidence is needed to undermine the belief that a
suspect is guilty? Who is right on this point? Dershowtiz or Bugliosi?
Casting aside any doubts about the conspiracy claims of
Simpson’s defense team, assume for the sake of argument that the LAPD did plant
the bloody sock. Would it be reasonable to conclude that OJ might be innocent? Bugliosi
firmly argues, “No” (Bugliosi, 1996). He points out that there was still enough evidence (both
physical and circumstantial) to convict Simpson that couldn’t have been fake or tampered with. Bugliosi cites the conclusive
evidence of Simpson’s blood at the murder scene, the bloody size-12 bootprints
discovered with a trail of OJ’s blood to the left (bandaged left hand the
morning after), no alibi for OJ during the 45 minute window when the murders
took place, the brutal nature of the killings (unlikely that drug dealers or
strangers would do this), ample evidence that OJ owned and wore the murder
gloves, and his prior history of spousal abuse. Furthermore, Bugliosi points
out that not a shred of evidence points in the direction of another suspect.**
Dershowitz, of course, is aware of the evidence that Bugliosi
cites. Despite the fact that they are both extremely knowledgeable and skilled
lawyers, they still disagree about whether the verdict was reasonable. If the
experts disagree, how can we establish whether a given verdict is proper or not?
One way to settle the dispute is to carefully examine an epistemic principle
that is at the heart of their disagreement. Here is what I take the underlying
principle to be:
The No Defeater
(ND) principle: In order to establish guilt beyond reasonable
doubt, there may be no defeaters to the evidence that establishes guilt.
I think it’s fair to say that Dershowitz endorses this
principle, whereas Bugliosi clearly rejects it. How plausible is it as a
general principle for establishing reasonable doubt? To test its plausibility, let’s
rewind the tape and suppose that the prosecution came across some additional
evidence. A video is presented to the jury that features OJ walking up North Rockingham
Avenue, entering his Bronco with a visibly bloody left hand. Would it be
possible to reasonably doubt Simpson’s guilt at this point? According to the ND
principle, it would be, provided that the jury were aware of some defeaters (e.g.
a planted bloody sock). But I don’t buy this for a second. For defeaters
to undermine OJ’s guilt, in this hypothetical case, they would need to undermine or cast
doubt upon the preponderance of evidence, not just some of the evidence. One piece
of damning evidence is enough to discount any of the defeaters presented by the defense team. Of course,
we could run the tape back and imagine a scenario where the video evidence, as
well as the rest of the evidence, would have been defeated. Suppose that the defense
team uncovered that the LAPD hired an OJ look-alike to appear on camera that
night to frame OJ. That would clearly undermine the prosecution’s evidence. But
absent such evidence, the video evidence alone would be enough to establish
guilt, even if there were some credible evidence that the LAPD planted a sock
or a glove.
The ND principle makes it much too easy to reach a reasonable doubt. A more plausible principle would be that in order for there to be a reasonable doubt about a murder suspect, the defeaters in question must undermine or establish serious doubts upon most of the evidence that incriminates the suspect. Why? Because we still need to explain why the rest of the incriminating evidence exists. If there are no reasonable alternative explanations for the majority of the evidence, the best explanation (i.e. the murder suspect did it) prevails. One can have reasonable doubts regarding some of evidence presented in a trial. And I'm sure the jurors did in the case of the Simpson case. But one cannot forget about the rest of the evidence and prefer far less likely explanations just because some of the evidence for a theory is suspicious.
In closing, I think Buglosi was right about the verdict, even if we were to limit ourselves to the evidence presented. There was no reasonable doubt that OJ did it, even if there were reasonable doubts about some of the evidence.
*The question is a normative rather than a descriptive one. Whether or not OJ did it is a factual question. I take it that whether the verdict was proper depends on the justification of the jurors’ beliefs (not the facts).
**In Bugliosi’s book “Outrage”, he documents additional evidence of guilt that was not discussed or presented to the jury. In brief: OJ’s behavior after the murder (suicide note, fled from cops with disguise and 9k of cash), circumstantial evidence of premeditation (purchase of disguise 2 weeks before the murder), incriminating testimony from OJ that he had cut his hand that night and the he left blood in several locations (but no explanation for how this happened).
Works cited:
Bugliosi, V. (1996). Outrage: The five reasons why OJ Simpson got away with murder. WW Norton & Company.
Dershowitz, A. M. (1996). Reasonable doubts: The OJ Simpson case and the criminal justice system (p. 55). New York: Simon & Schuster.
Toobin, J. (2015). The Run of His Life: The People VOJ Simpson. Random House Trade Paperbacks.
