teacher background information FSE09 Case studies In the hood of the jacket, there was a small amount of soil. More larval scenopinids and adult dermestid beetles were found in the soil when it was sorted by hand. The forensic entomologist also found an adult histerid beetle and mites. History of forensic entomology Forensic entomology is not a new science. The first recorded case of forensic entomology was in China in 1235 AD. After a person was found dead, all the peasants in the village were required to bring their farming tools to the village centre. The killer’s weapon was identified because there were flies feeding on the tiny amounts of blood attached to the tool. The forensic entomologist estimated a PMI of 5276 days by comparing the results with other data already collected. This estimate was lowered to slightly over 52 days, based on the condition of the larval skins of the dermestid beetles, which were in good condition. The mites recovered were also consistent with this time frame, and because other mite species weren’t present, the forensic entomologist reckoned the time since death to be closer to 52 days. Case Study 1 The skeletal remains of the buried young girl from Hawaii (adapted from ‘A fly for the prosecution: how insect evidence helps solve crime’ by M. Lee Goff) In the decomposition studies used for comparison, the last observed larval activity for dermestid beetles was on day 51. Usually, the larval skins decompose rapidly when exposed to the weather. The fact that these skins were in excellent condition and could easily be identified indicated that they had been shed recently. The remains of a female child (30 months of age) were recovered from a shallow grave on a narrow ledge in Oahu, Hawaii. The remains were buried in dirt and gravel, and some bones were partially exposed. Other bones were scattered on the surface. The skull was facing upward, and the lower jaw was located about a meter from the skull. In the meantime, police investigators were dealing with conflicting accounts of the crime. On 3 May, the girl’s father stated that his daughter had been kidnapped on the night of 2 May. He said that two men forced him and his daughter into a car, dropped him off in Honolulu and beat him. He said the kidnappers ran off with his daughter. The father was treated at the hospital for injuries. According to the father’s story, these events occurred 51 days before the discovery of the body. The pathologists at the morgue examined the body and found the girl’s skull, jaw, most of the ribs, the pelvis and legs and left arm. The right arm was missing. Small bones of the left foot appeared to have been chewed and so did the bones of the left forearm. This indicated that a large animal had attacked the body after death. The girl was wearing a hooded jacket and a pair of running shoes. The next day, the girl’s right arm was found at the burial site. When the story appeared on the news, two men came forward and told the police that they had beaten the father but that he had paid them to do so. When the father heard the men’s story, he changed his own story. He told police that he was hiking with his daughter on 2 May but had slipped and dropped the girl over a cliff. He said that he tried to revive her but failed and buried her in a shallow grave. He admitted that he made the kidnapping story up. The body was examined but only a small number of insects were found on the body. Empty puparial cases (cocoons) of the calliphorid Chrysomya rufifacies (a type of blow fly) were attached to the skull under the scalp, which had largely been eaten away. Adult dermestid beetles, Dermestes maculatus, were present on the bones, and third instar larval skins of that species were observed in areas under the scalp, inside the skull, and on the leg bones. The larval skins of the dermestid beetles were in good condition and did not appear to have been exposed to the weather. Larval scenopinids (Diptera - flies) were collected from the scull near the bases of the hair. Adult clerids, Necrobia rufipes, were recovered from the bones of the left foot. A silverfish (Thysanura: Lepismatidae) was recovered from the body bag. Forensic investigations: Case studies (teacher background information) FSE09 | revised June 2013 | © The University of Western Australia The police did not believe the father’s accident story and charged him with murder. By the time of the trial, the father had changed his story again. The only aspect of the case that had not changed was the time of death estimate that the forensic entomologist provided. The jury accepted the forensic entomologist’s testimony but did not believe the father’s story. Potentially, the father’s story could have fit in with the estimated time of death but he was not credible to the jury. The father was charged with murder and is serving a life sentence. page 1 Licensed for NEALS Case Study 2 Case Study 3 http://research.missouri.edu/entomology/cas estudies.html Robert Donald Auker was convicted of the murder and kidnapping of his former wife Lori Ann Auker. Lori Ann’s body was discovered on a hot day, 12 June 1989 by a young woman who was walking down a dirt road near her grandparent’s house. She smelled a bad odour, investigated and found a decomposing body wearing a jacket, jeans and sneakers. She rushed home and her family contacted the police. The pathologist, Dr Mihalakis testified to the court that the cause of death was homicide, most likely between seven and ten knife stab wounds in the back and chest area. Dr Mihalakis used Dr Kim, a forensic entomologist, to confirm the approximate time of death. A few years ago, on 4 June, the body of a girl was found alongside a rural highway in North America. An autopsy revealed that she had died of multiple head and neck wounds inflicted by a heavy sharp object. Her brother had reported her missing approximately 4 days prior to the discovery of the corpse. She had last been seen alive on the morning of 31 May in the company of a 30 year old army sergeant, the primary suspect. While considerable circumstantial evidence supported the theory that the victim had been murdered by the sergeant, an accurate estimation of time of death was crucial to establishing a possible link between the suspect and the victim at the time when death occurred. Dr Mihalakis collected the insects present on and within the corpse and gave them to Dr Kim who examined them. Dr Kim stated in court that he was able to estimate the time of death by analysing the insects. He explained that the ambient air temperature and the physical site of the body affected the rate of development. Dr Kim used a climate report from the national weather service and a description of the autopsy and scene to help determine the time of death. Several estimates were offered by medical examiners and investigators. These were based largely on the physical appearance of the body and the extent to which decomposition had occurred in various organs. Numerous fly larvae, adult flies and other insects were collected from in and around the victim’s wounds. Some of the larvae were collected alive and reared to produce adult flies for species identification. Others were placed immediately into a liquid preservative to identify the developmental stage. Reports describing the condition of the body when found and detailing autopsy procedures and results were reviewed. Weather data, including maximum and minimum temperatures, incidence of rainfall, cloud cover, wind speed and direction, and relative humidity were obtained from a weather station located a short distance from the crime scene. These data indicated the environmental conditions to which the body and its associated insects were exposed. Dr Kim identified samples of insects found on the victim and examined a photograph showing a mass of insects on the body and in the body bag. Dr Kim took the average temperature during the time the body had been missing, the maturity of the insects present and the stage of decomposition into account. He determined that the body had been decaying for between 19 and 25 days. Lori Auker was identified using dental records and was last seen wearing clothing like that found on the corpse. Robert Donald Auker was connected to the crime by film from an ATM video camera film from 24 May (the day Lori went missing) and through strands of cat and human hair. Photographs of the corpse and insects were presented to the jury to assist in their understanding of forensic entomology. Robert Donald Auker received a death sentence upon his conviction. Forensic entomology helped estimate the time of death (19 days), which aided in the jury convicting Robert Donald Auker of murder. Based on this total array of evidence, entomologists determined that the first insects to colonize the body had arrived on May 31 when the accused was found with the victim. On questioning he admitted to have murdered the girl by striking her six to eight times with a small hatchet sometime around noon on May 31. Subsequently, he entered a plea of guilty to the murder charge and was sentenced to life in prison without parole. Forensic investigations: Case studies (teacher background information) FSE09 | revised June 2013 | © The University of Western Australia page 2 body and the extent to which autolytic changes had occurred within various organs. Case Study 4 http://research.missouri.edu/entomology/cas estudies.html The maggots observed in and around the body during the autopsy were identified. Rearing of maggots to the adult stage was not possible as none of the specimens had been maintained alive. Soil samples yielded no additional specimens. Numerous photographs depicting the crime scene, the surrounding vegetation and terrain, and the body itself were examined. In November a partially clad woman’s body was found by passing motorists in a wooded area approximately 50 feet from a welltraveled highway in suburban Washington, DC. The deceased was a young, adult black female, weighing approximately 116 pounds. Her body was cold, rigor mortis was absent, and only minor external decompositional changes were evident. The victim had died of multiple stab wounds to the chest and neck. Climatological data, including maximum and minimum temperature, cloud cover, rainfall, wind speed and direction, and relative humidity were obtained from a National Weather Service (NWS) observatory located less than a quarter of a mile from where the victim’s body was found. Additionally, reports describing the condition of the body when found and detailing autopsy procedures and results were reviewed. During the autopsy, several large maggots were observed migrating away from the corpse. This behavior is characteristic of fully developed, post-feeding blow fly larvae. Several additional maggots were removed from the neck wounds and clothing. The victim was subsequently identified as a 21 year-old mother who resided with her infant and parents in an urban apartment complex in southeast Washington, DC. She had been reported missing by her parents 18 days prior to the discovery of her body. She was last seen alive during the early morning hours on Wednesday, 26 October in the apartment of the primary suspect, who had a history of sexrelated offenses and violent crimes and had recently been released from prison. The largest fly larvae inhabiting the remains were fully engorged third instar larvae and post-feeding larvae of Calliphora vicina. One specimen showed morphological signs of pupation. Based on the temperature records for the relevant period, the number of days necessary for Calliphora vicina to develop from egg to prepupa was calculated. Because the average daily temperature to which the developing flies were exposed was cool (10oC) and because too few larvae were present within the corpse to elevate microenvironmental temperature, the postmortem interval was estimated to be 15 days. Witnesses recalled having seen a man and woman struggling and having heard a woman screaming in the vicinity of the apartment house during the early morning hours 18 days prior to her discovery. Hair from the victim’s head and pubes was found on bed sheets in the suspect’s apartment. A shoe belonging to the deceased was subsequently found in a secluded urban woodlot located a short distance away. Samples of blood and hair taken from the suspect’s car also were identified as belonging to the victim. An analysis of auto carpet fibers, removed from the victim’s clothing, further demonstrated that she had been transported in the same vehicle. Based on the entomological data and the other evidence acquired during the police investigation, the suspect was arrested and charged with first degree murder, kidnapping, and felony rape. He was eventually tried, found guilty of all charges, and was sentenced to a lengthy prison term. Later it was learned that he had murdered the victim during the early morning 18 days prior to discovery and had hidden the body, by covering it with tree branches, a mattress, and other debris, in a nearby urban woodlot. Three days later, again during the early morning hours, he had transported the corpse to the location where it was found. The materials used to hide the body may have prevented oviposition by adult Calliphora vicina during the first few days following death. The fifteen day postmortem interval was valid. While considerable circumstantial evidence pointed to the suspect, an accurate estimate of the time of death was critical in establishing the sequence of events surrounding the death. Several conflicting estimates of postmortem interval, varying from 2 to 8 days, were offered by medical examiners and case investigators, based primarily on the physical appearance of the Forensic investigations: Case studies (teacher background information) FSE09 | revised June 2013 | © The University of Western Australia page 3