Potting Soil and Quick Dry Cement: Circumstantially Constructed Cases.

In Florida this month, Ashley MacArthur was tried and convicted for first degree murder. 33-year-old Taylor Wright’s body was discovered on a 30-acre tract of land owned by the Defendant’s family. The former police officer’s body was buried underneath a concrete slab covered with potting soil. The investigation lead to Ashley MacArthur, a former crime scene technician. Among other pieces of evidence presented by prosecutors was a video of MacArthur buying quick dry concrete and potting soil a day after the victim was missing.

From time to time, the folks at the Law and Crime Network ask me to commentate on cases they cover. The concept of circumstantial evidence vs. direct evidence came up in this case, so I decided to share my thoughts with you. Fair warning: I love this stuff, and could talk about it all day. Circumstantially constructed cases fascinate me (I even get to teach a class about it!), and this one is no exception. Some the most famous cases you’ve heard about were constructed circumstantially. Oklahoma City Bomber Timothy McVeigh immediately comes to mind (more on that trial in a few months!). In this post, we’ll define and discuss circumstantial evidence in the MacArthur trial, and its role for jurors. 

First, a note about commentating. I only talk about cases that would never land in front of me – only cases from outside Texas. I never take sides. I only try to explain the legal concepts at play in the case, or the legal strategies employed by the lawyers.

About 2 years ago, I was researching the question of whether a person could be convicted of murder even if the body of the deceased was not recovered or there was no determinable cause of death. A complicated question and discussion we can save for another day. And yes, I find legal questions like these terribly interesting. Along the way, however, I kept coming across cases in Texas citing a treatise written by a guy named Alexander Burrill. I did what any legal researcher in 2019 would do: I googled him and found “A Treatise on the Nature, Principles, and Rules of Circumstantial Evidence” available online.

Published in the 1860’s, I think it’s amazing. The best part is that it’s in the “public domain,” so you can have your own copy by clicking here. In it, he does a masterful job of explaining the difference between circumstantial and direct evidence that I’ll share with you.

Let’s start with the start – where does the word “circumstantial” come from? “Circumstances, according to the etymology of the word, are certain minor facts standing around (Latin: –Stantia (Standing) –Circum (around)) a principal fact, and which as from so many distinct surrounding points, shed a converging light upon it, as a common centre.” (Page 8). What is a “Principal Fact?” It is “in all cases, composed of two others; first, the fact that a crime has been committed; and secondly, the fact that the accused has been instrumental in its commission.” (Page 119). In other words, for jurors, the principal fact is whether the defendant committed the crime for which he or she is charged: Guilty or Not Guilty.

There are two types of evidence: Direct and Circumstantial evidence. Direct evidence is the proof of the principal fact without processes of inference, deduction, reason, common sense, or experience. This type of evidence is proven in Court by witnesses with personal knowledge of the fact. “I saw person X shoot Person Y.” A good example of a direct evidence case? Jack Ruby killing Lee Harvey Oswald on live television.

Circumstantial evidence requires some analytical process – inference, deduction, reason, common sense, or common experience – in order help jurors answer their question. One of the numerous pieces of evidence in the People of California vs. Charles Tex Watson was Tex’s fingerprint, recovered on the outside of the front door to Sharon Tate’s house on 10500 Cielo Drive. No one could say, “I observed Tex touching that door at that exact location, and he did, in fact, leave a fingerprint.” However, the fact that the cleaning lady recalled cleaning the door a few days before the killing, and the orientation of the print was consistent with Tex being on the inside of the house grabbing the outside of the door as he walked or ran out creates a strong presumption that he was inside the house sometime after the cleaning lady cleaned the door and before the police secured the scene and collected the print. Since that window of time includes the commission of murders, there is some indication that Watson was involved.

Same, same for the MacArthur jurors tasked with determining the “Principal Fact” – Did MacArthur murder Wright? Since the potting soil and cement comprise a part of the crime itself, and since MacArthur was observed with them during the window of time which includes the commission of the murder, there is some indication that MacArthur was involved.

The location at which a body is discovered is another fact that may shed light on the principal fact because that the person who put the body there had access to that location – either because they were familiar with it or because they were in the area at the time and happened upon it. Since the property where Wright’s body was found was in fact owned by the Defendant’s family, she had access to it, and was familiar with it.

Does this mean that she is guilty of murder? No. But, there are now two “circumstances” that indicate she was somehow involved: possessing some of the instruments used to accomplish the crime (soil and cement) coupled with access to and familiarity with the location where part or all of the crime was committed.

One of these circumstances by itself sheds some light on who committed the murder; considered together, however, their shedding light becomes significantly brighter. If you add the fact that the MacArthur was accused of stealing $34,000 from Wright, the light becomes brighter still.

“It is by circumstances like these, that light is shed along a whole course of criminal conduct…pointing out the perpetrator himself, by connections and indications as conclusive as though the facts had been directly proved by actual eye-witnesses. It is of [facts such as] these, presented in every variety of modification and combination, according to the crime, the parties and the nature of the case, that circumstantial evidence, in the broadest sense of the term, is found to be composed.” (Page 128-129).

Developing and explaining the strength of the connections between circumstances like those discussed above are the stuff trials are made of. Jurors listen to the bits and pieces put before them one witness at a time, constantly measuring each, reevaluating their strengths as new evidence is admitted. This calculation does, or does not, lead to reasonable doubt in the minds of jurors.