If jurors are subject to public scrutiny and criticism, then surely medical examiners who identify homicide victims—and as a result force private citizens into the jury box at murder trials—must also be subject to public scrutiny and criticism.

In this era of televised trials, the cameras rarely turn on the jury; but they often focus on the witness stand where expert witnesses, including MEs, sit. Some MEs’ faces turn up on TV more often than others.

If there were a Sidewalk of ME Stars in Atlanta (where CNN’s In Session originates), one cement slab would surely be devoted to a female Tennessee medical examiner with a long, difficult-to-spell name. Because her name is so long, and because I’m not comfortable criticizing most forensic experts (I’m not a lawyer or forensic expert), I’m going to omit this woman’s name.

Problematic Science in Court

It may simply be a coincidence that a certain ME has testified in three trials that exemplify for me the problems with scientific presentations in court: the trials of John Collett, Raynella Dossett-Leath, and Eric McClean. But it seems unlikely to be a coincidence that each of these defendants is free today (at least free on parole or bond). Each trial had an outcome unfavorable to the prosecution for which this ME testified. Mr. Collett was found not guilty, Ms. Dossett-Leath’s trial ended in a hung jury, and Mr. McClean’s trial ended in a conviction on minor charges and a sentence of parole.

Science in Court for the Finders of Fact

In American law, the jury is the “finder of fact,” not the cops, not the prosecutor, not the judge.

Sidebar: This isn’t true in most countries. The issue is complex, and I will tackle it soon, but not now.

What “finding fact” means is that the jury examines the evidence and decides which of it is valid and which is not. In a murder trial this includes the ME’s testimony as well as autopsy photos and possibly the autopsy report. (I believe in many trials, the written autopsy is referred to by ME witnesses but never given to the jury.)

Ideally, an ME conducts every autopsy according to the “scientific method.” The method is a series of steps:

1. Pose a logical sequence of questions about a physical phenomenon (such as, What was the “cause of death?” What was the “manner of death?”)
2. Conduct background research (such as analyzing blood and stomach contents)
3. Construct a hypothesis (using Ockham’s Razor, that is, the simplest explanation is usually the truth)
4. Conduct an experiment based on the hypothesis
5. Analyze the results of the experiment
6. Draw a conclusion and support it with the experimental data

Note that the first step is to list all the reasonable questions. An ME must begin by questioning the cause of death and not jump immediately to the question about the manner of death. An ME must know what killed a person before she can declare the manner of death to be a homicide. Research must first be conducted into the cause of death, hypotheses tested, data analyzed, and conclusions drawn before asking the question: Was the cause of death natural, accidental, suicide, or homicide?

The final step in the scientific method is designed to communicate and persuade others of scientific conclusions. What that means for an ME is that the autopsy report must be persuasive and, in the case of homicide, must convince a jury.

Sidebar: I believe most jurors don’t understand that all science is subject to review and contradiction. Non-scientists don’t understand that scientific truth changes and evolves each time new experiments are conducted and new conclusions are reached. In other words, scientists require good rhetoric as much as a trial lawyer does.

Rules of Evidence

In most criminal trials, the prosecution must justify each of its items of evidence to a judge before any evidence can be presented to the jury. In America, the judge doesn’t declare items of evidence to be valid—only to be admissible and relevant under a very complex set of rules.

These “rules of evidence” derive from decades and sometimes centuries of common law and case law. None of the rules involve the scientific method.

A 1990s era Supreme Court decision, Daubert v. Merrell, attempted to banish “junk science” (evidence not deemed scientific by the science community) from courts. Unfortunately, the decision did not address the issue of experts who purport to be practitioners of legitimate scientific disciplines, but who—either carelessly or intentionally—fail to adhere to the scientific method.

Sidebar: For example, in 2002 a Bell Labs physicist, Jan Hendrick Schon, was discovered to have falsified data and claimed to have developed an organic transistor when he had not. If his claim had been true, it would have destroyed most of Silicon Valley and consequently a major segment of American industry. It was all a lie, and his fellow physicists did not discover the fraud through the much-vaunted “peer review process” until a young researcher noted that Schon had presented identical data sets as evidence of different conclusions.

In a murder trial, the autopsy or ME’s testimony is always admitted into evidence. The law does not contemplate the possibility that an ME would falsify an autopsy report or fail to adhere to the scientific method.

Autopsy Protocols

Well-known, standard procedures govern the conduct of an autopsy (Midwest Autopsy has a nice, clear description of the steps in an autopsy). The autopsy itself is step 2 in the scientific method, the background-research step.

Perhaps the most important step in an autopsy—certainly in homicide cases—is determining the time of death. ME technicians collect evidence of this at the place where a case of suspicious death occurred. In the body they note rigor mortis, livor mortis, and should also take the liver temperature. If they do not take a liver temperature at the scene, then the ME should take the temperature as soon as the body is received in the morgue. Failure to do so can cause a suicide to be identified as a homicide and the wrong person to be identified as a murderer simply because she doesn’t have an alibi.

The medical examiner must not approach an autopsy with an intellectual bias toward either the cause of death or the manner. As Dr. Friedlander of Midwest Autopsy notes, “At least a fifth of autopsies reveal a cause of death other than was believed clinically.”

The autopsy report and death certificate comprise the final step in the scientific method, the argument and persuasion.

CSI Involvement

In cases of suspicious death the police will take custody of the body, rather than a physician. Police crime-scene investigators will collect evidence from the body and around the place where it was found. Then, after the body is received at the morgue, either an ME or a crime-scene tech will remove all clothing and preserve it and will collect further hair and fiber evidence.

In such cases, the detective in charge of the investigation into the suspicious death will attend the autopsy (or should) to ensure that the ME doesn’t overlook anything or make obvious mistakes. The ME and the detective may discuss the circumstances under which the body was found. This discussion becomes part of the ME’s research. It also tends to guide the ME to ask questions and pose hypotheses.

Clearly, this police information has the potential to bias the ME. This is apparently what happened in the investigation into the death of Sgt. Drew Peterson’s second wife, Kathleen Savio, for instance. A good ME, of course, will resist the temptation to jump to conclusions. (It’s notable that the Savio autopsy was conducted by a pathologist, but the initial, mistaken cause of death as accidental was determined by a coroner’s jury.)

Put simply, nothing in criminal law prevents medical examiners from making mistakes or presenting false information to a jury.

In Part II I will examine a certain medical examiner’s testimony in three murder trials.