It was a televised debate between experts that dominated the 1999 murder trial of 38-year-old Thomas D. Huskey, accused killer of four women. This was the first documented serial killer in Knox County, Tennessee, and prosecutors were seeking the death penalty.  The two sides focused not only on the issue of his mental state at the time of the offenses, but also used insect analysis to make an issue of the time of death of two of the victims.

Prostitutes dubbed Huskey the "Zoo Man" because he once had worked at the Knoxville Zoo and he liked to take women close to it for sex.  His father had been an elephant trainer, so he was raised at the zoo, but eventually Huskey was fired for abusing the animals. 

The first victim was discovered on October 20, 1992.  She had been buried in a shallow grave in a remote wooded area in East Knox County.  Over the next few days, three more bodies of women were found in the same area, all but one of them known prostitutes.  The police quickly linked them as the work of one person.

On October 21, Huskey was taken into custody for solicitation, and in four separate and conflicting statements, he then confessed to murder.  He also said he had raped three of the four women, although the autopsies did not yield any conclusive evidence on that score.

While five mental health practitioners debated over whether Huskey had multiple personality disorder (known today as dissociative identity disorder, or DID), experts on insect activity in corpses tried to establish when the victims had died.

Dr. Henry Goff offered testimony for the defense on forensic entomology.  That is, he studied the maggots on the decomposing body of one victim, concluding from the age of the larval stages that Huskey could not have killed her.  He was in custody on October 21st and Goff estimated that the earliest the victim could have died was October 23rd.  The theory that guided his assessment is that certain insects are attracted to bodies soon after death to deposit eggs.  Estimating the age of the insects from predictable stages of development offers a rough idea of the time that has elapsed since death, also known as the minimal postmortem interval (PMI).

Goff also did insect studies on another corpse to support the idea that she could have been killed by another man---her own boyfriend.  The original time of death was estimated by the state's expert as October 14th, but she was apparently seen on October 17th with her suspected killer.  In that case, the state's expert could have been wrong in his conclusions.

With any time of death estimate, there is room for doubt, and the prosecution forced Goff to admit that insect activity can be affected by weather and environmental variables.  However, Goff pointed out that he and the state's expert relied on all the same data to come up with their conflicting conclusions.  Nevertheless, the window of uncertainty can range from eight to twenty-four hours—a time period that was obviously critical in the Huskey case.

Given how inexact the entomological interpretation was, the defense relied on the big guns of mental health.  With the idea that Huskey did in fact commit the murders, three experts examined the defendant, and psychiatrist Robert L. Sadaff said, "It is clear from reviewing the records and examining Thomas Huskey that it was the alter ego Kyle who was responsible for the violent behavior, including the rapes and murders."  Kyle apparently admitted to the killings and he (not Huskey) also made the confessions to police.  (The defense would later claim that these confessions were manipulated.)   

The prosecution charged that the personalities were faked, and in fact were based on characters in a daytime soap opera, Days of Our Lives.  Another inmate contended that Huskey had read the book, "Sybil," and had admitted he was going to use this ruse in his trial.  It was also true that the "facts" about Huskey's sordid past on which the defense experts based their diagnosis had not been substantiated. His alleged abusers were never located and his own mother denied ever seeing manifestations of other personalities.  As a child, Huskey had exhibited an active fantasy life, so his "recollections" of violence were highly suspect.

After five days of deliberation over whether to find him Guilty But Insane, the jury ended up saying that he suffered from a mental illness but they were unable to make a decision about his degree of responsibility.  Thus, his 1999 trial resulted in a hung jury.  Nevertheless, it did bring some attention to forensic entomology, and Knoxville is certainly the place to be for some of the best information on the subject.

One of the reasons that time of death estimates leave so much room for error is the fact that there has been little focused study of the variables.  Only one facility in the country makes this their primary work: The Forensic Anthropology Center at the University of Tennessee at Knoxville.