Burning Evidence

It's all too common these days for the police to arrive at a crime scene only to find the body of the victim burned beyond recognition. The body may have been placed in a pit or shallow grave and then dowsed with an accelerant and set on fire. This may have been repeated a number of times to ensure the body's destruction. Often a body is found burned in a car and made to look like an accident or in a house set on fire by an arsonist. People generally believe that burning a body destroys the evidence of how a victim was killed. A wood fire burns at a temperature of between 800 and 900 degrees centigrade. In a crematorium where a body is supposed to be fully reduced to ash, the temperatures are considerably higher, varying from 1100 to 1500 degrees centigrade. Even in this situation, the bones are not fully decomposed and the large fragments are then ground up in the final preparation.

In Drexel, Missouri in August of 2006, Michael Lee Shaver, age 33, was arrested for the murder of seven people. Shaver confessed that he murdered them and then dismembered the bodies and burned the parts in the fireplace in his bedroom. Afterwards he spread the bone fragments around his back yard. In August of 2002, two young girls disappeared in Soham, England. Ian Huntley, a caretaker at the private school that the girls attended. had abducted them and murdered them. He then tried to hide the crime by repeatedly burning the bodies in a six fool wide ditch. However, the attempts were only partially successful and eventually the police found the partially burned bodies of the girls. Finally, Hugo Selenski, thought to be a serial killer, was tried on charges of murdering and burning the bodies of two individuals. Selenski claimed that he burned the bodies and spread them his back yard. Because of lack of evidence of his direct involvement he was acquitted on the murder charges but found quilt of abuse by burning of a corpse. Police have found evidence of at least five bodies in his yard.

If a murderer is meticulous and smashes the pieces of bone that do not burn, then there will be little chance of developing information about how the victim died. However, most murders are impulsive, and after one or two attempts to burn the body, the perpetrator will probably give up and simply bury the remains. In this case, the forensic anthropologist, upon examining the remains, may be able to determine certain things about what happened to the victim before the fire.

Arson Fire to Cover a Murder

In the case of arson fire or of a faked car accident and fire, the body is generally badly decomposed, but the skeletal structure remains largely intact. If a person is alive but unconscious before they are burned, the burned body will assume a pugilistic posture. This term arises from the similarity of the posture to that of a boxer in the ring; the arms are raised up in a defensive position and the hands are tightened into fists. The legs may be bent into a defensive stance as well. As a body burns, the muscles contract and the flexor muscles, being stronger, overpower the extensor muscles, thus giving rise to the pugilistic position of the body. If a burned body is found with one or both hands with the fingers extended and not in the pugilistic position (as a fist), this would indicate that one or more of the three bones of the arm had suffered a fracture before the victim died. This fracture would most likely have occurred from some form of blunt force trauma or from a beating.

Reading the Bones

The large bones of the leg and arm are the most reliable for determining bone damage. The forensic investigator versed in burned bone analysis looks at both the macromorphology and the micromorphology of the fracture area. Perimortem, or pre death, fractures show up as relatively smooth breaks which continue uniformly through both wet bone and burned bone material. Due to extension and tension of the bone at the time of the break, these fractures will exhibit a pattern of microfractures, resulting in a typical butterfly pattern to the fracture. In contrast, postmortem fractures caused by the burning and drying out process exhibit fractures that are blocky and stepped in appearance. Human bone is composed of minerals, collagen and water. Water makes up 6% of bone by weight and 11% by volume. When the bone is burned, heat dehydrates the bone, driving out the water and destroying the collagen structure. Burning bones are subjected to heat induced expansion and shrinkage, and the existence of a thermal gradient, depending on the location of a specific bone in the resulting fire.

If a body has been dismembered before burning, the tool used (hatchet, saw, large knife, etc.) will leave a characteristic pattern of cut marks on the bones. Often there are several marks made by the same weapon, and these usually represent false starts made by the perpetrator in attempting to saw or cut through the bone. These marks often present as "W" or "V" shaped marks that can provide valuable evidence about the type of tool used for the dismemberment, and guide investigators in the search for a weapon. The burning process leads to dehydration of the bones, but the relative pattern of the cut marks may still be maintained.

One of the more disturbing recent cases where a burned body was found by investigators occurred earlier this year in Cincinnati, Ohio. The foster parents of a three year old disabled child reported him missing a week after they had returned from a family reunion is Kentucky. Hundreds of police and volunteers searched the area for several days, but to no avail. Police then discovered that the foster parents, not wanting to take the boy to the reunion, had wrapped the child up like a cocoon and left him in a closet for two days while they went to Kentucky. When they returned, the boy was dead. While others were searching for him, they apparently went in the next county, attempting to conceal the crime by burning the body repeatedly--two or three times.