Most of us know this, but it’s worth a refresher on how criminal investigations are conducted — and how that is influenced by what the criminal justice system needs to prove. One of the oldest “truisms” of criminal investigations turns on an aphorism colloquially known as “MOE.” MOE is the acronym for “Motive, Opportunity & Evidence.” Investigators focus on this three-legged stool because each leg constitutes an important element in a successful criminal prosecution.
Let’s consider each in turn, using the Robert Hansen case as an example.
Robert Hansen Leaves Courtroom, Covers Face (Hansen is 4th from left; courtesy Anchorage Times)
- MOTIVE : As most of us know, motive defines “why” the accused committed the crime. In Robert Hansen’s case, his motive for murder was closely tied to his desire to continue his kidnappings and rapes. Dead women don’t talk. Over time, Hansen started killing them for the “thrill;” his motive having evolved to include the “sexual surge” he got from committing murder.
- Why is this important? The defendant can — and will — argue that he had no reason to commit the crime for which he is accused. That argument is strengthened when the prosecution is unable to present a credible motive linking the defendant to the crime. Juries — human beings — prefer to believe that everything happens for a reason.
- In some crimes, moreover, motive helps investigators identify accomplices; this is not trivial: depending on the motive, accomplices can go on to commit additional crimes.
- OPPORTUNITY: This leg of the stool refers to the accused having access to the crime scene and/or victim, either physically or virtually. In Robert Hansen’s case, he owned a bakery that was close to the Anchorage “strip,” where dancers and prostitutes frequented. His work hours — early in the morning — put him in physical proximity to his victims, who worked similar hours.
- Why is this important? If the accused can prove he was elsewhere when the crime occurred, then the prosecution has a problem. That problem is not absolute: the accused could have hired a hitman or committed a virtual crime through electronic means. In these cases, the prosecution needs to prove that the accused has the ability to “push those buttons.”
- EVIDENCE: This refers to the forensic findings that link the accused to the crime: DNA, fingerprints, shell casing and weapon matches, etc. Most crime dramas emphasize this aspect of MOE — not only because the exposition is “sexy,” but because it is considered the most irrefutable. In Robert Hansen’s case, prosecutors found that his shell casings matched those found at crime scenes. They found mementoes belonging to victims in his attic. They matched his semen to samples found in Cindy Paulson. Speaking of Cindy Paulson, they also had eyewitnesses who could identify him as the person who kidnapped, raped and threatened them.
- Why is this important? Evidence is what ultimately links the accused to the crime. If investigators find the DNA of the accused on a murder victim, the accused is positively linked to the criminal act. Same for fingerprints, shell casings or, for that matter, disguises found in the perpetrator’s possession that match witness descriptions or have been seen on surveillance cameras.
There are, of course, exceptions to the three-legged stool requirement. Circumstantial cases, for example, may lack the kind of explicit evidence that prosecutors prefer — but if the other two legs of the case are strong, they can be successfully prosecuted. Similarly, a case lacking an explicit motive can be successfully prosecuted if there are ample evidenciary findings and convincing proof of opportunity.
Failure to prove MOE points toward innocence instead of guilt
That said, a breakdown in any of these investigatory pillars can threaten the effectiveness of a criminal prosecution. Indeed, seen from the opposite perspective, failure to prove one or more of these three components can — and often does — point toward innocence instead of guilt. This is as it should be — the U.S. system operates on the presumption of innocence (well, it should; sometimes its seems that the public has grown weary of “innocent until proven guilty”).
(1) MOE was strong enough against Robert Hansen that, upon being confronted with it, he decided to plead guilty rather than go to trial.
(2) Some folks are downplaying the importance of motive in the Las Vegas massacre. Perhaps it will, in fact, prove unknowable. But, again, motive can point to accomplices. As such, it is not something investigators can or should casually discard.
Purchase Butcher, Baker