Bite Mark Identification in the Ted Bundy Serial Murder Case

     The identification of bruises or abrasions usually in the shape of two semi-circles or brackets as a human bite mark made by a particular set of teeth is a function of forensic dentistry referred to as bite mark identification. This form of impression identification, also called forensic odontology, is based on the assumption that no two people in the world have front teeth that are identical in thickness, shape, relationship to each other and patterns of wear.

     The process of comparing a bite mark to a known set of teeth is not unlike the identification of latent fingerprint, footwear and tire track impressions. Bite mark wounds are found on victims of murder, rape, and child molestation. This type of crime scene evidence is preserved by life-size photography, tooth mark tracings onto transparent sheets and dental casts of the impressions themselves. A suspect might be asked to bite down on a pliable surface for an impression sample, have a cast made of his teeth, or both. Usually, connecting a suspect to a victim through expert bite mark testimony will be enough evidence, by itself, to sustain a criminal conviction. For this reason bite mark evidence must be 100 percent reliable. Unfortunately it is not even close to that.

     The field of bite mark identification exploded in the 1980s. Hundreds if not thousands of defendants went to prison on the strength of bite mark testimony. Although bite mark identification has been a recognized branch of forensic science since 1970, it was the 1979 trial of serial killer Ted Bundy in south Florida that put this form of identification on the map the way the O. J. Simpson murder case popularized DNA profiling in the mid-1990s.

The Ted Bundy Serial Murder Case

     After killing 30 to 100 college-aged women in the states of Washington, Utah and Colorado, Theodore Bundy entered a Florida State University sorority house in Tallahassee where he sexually assaulted and murdered two Chi Omega sorority members. The police arrested him a short time later in a stolen car, then put him on trial for murder.

     The prosecutor had plenty of nonphysical evidence against Mr. Bundy, but it was circumstantial and didn't place him in the Chi Omega murder room. The killer had left a hair follicle on a crime scene stocking mask that looked similar under a microscope to samples from Bundy's head. But hair identification wasn't enough by itself to carry a conviction. The rapist had left traces of semen, but these murders were committed more than ten years before the dawn of DNA analysis.

     If the Dade County prosecutor had any chance of convicting Ted Bundy he would have to connect him to the murder scene through a bite mark wound on one of the victims. To do that the prosecutor called on Dr. Richard Souviron, the chief odontologist for the Miami-Dade County Medical Examiner's Office. He also enlisted the services of Dr. Lowell J. Levine, a forensic dentistry consultant to the New York City Medical Examiner's Office. To round out his battery of experts the prosecutor brought in Dr. Norman Sperber, an odontologist with the San Diego and Imperial County Medical Examiner's Office in California. These three forensic experts comprised the nation's most renowned bite mark analysts.

     Dr. Souviron took the stand and testified that the sorority house attacker left a postmortem double-bite mark on one victim's left buttock. He had bitten once, turned sideways, them clamped down again. The killer's top bicuspids and his lateral and central incisors had remained in the same position, but he had made two wound brackets with his lower front teeth. When he photographed Ted Bundy's teeth Dr. Souviron noticed they were of uneven length, chipped and oddly aligned, factors that helped individualize the defendant's bite mark pattern. To illustrate for the jury that Mr. Bundy's teeth matched the murder scene wound, Dr. Sourviron laid a photograph of the defendant's teeth, depicted on a transparent sheet, over an enlarged photograph of the bite mark. The bottom edges of Bundy's teeth lined up perfectly with the crime scene wound.

     Dr. Norman Sperber and Dr. Lowell Levine took the strand and lent their expertise to the identification. Bundy, representing himself, brought in his own dental expert, an odontologist from Maryland who testified that "the dental pattern [bite mark] is one I'd expect to find in 20 percent of the population of male Caucasians." The defense expert didn't say the bite mark on the victim couldn't have been Bundy's, he just wasn't willing to identify the wound as coming from the defendant to the exclusion of all others.

     The jury found Ted Bundy guilty as charged. The judge sentenced him to death, and ten years later Ted Bundy was executed. Before his execution he confessed to the sorority house killings and dozens of other lust murders.

     The Ted Bundy case established the credibility and usefulness of forensic bite mark analysis, and for a while placed it on the same level, in terms of reliability, as latent fingerprint identification. But following a series of high-profile misidentifications in bite mark cases, this form of impression analysis was no longer considered as reliable as latent fingerprint identification. Today, in most states, odontologists are not allowed, by law, to state unequivocally that a defendant is the source of a bite mark. The most these experts can say is that the questioned bite mark is consistent with having been made by the defendant's teeth. 

Bite Mark Identification: Discredited Evidence

     The identification of a series of bruises or abrasions, usually in the shape of two semi-circles or brackets, as a human bite mark made by a particular set of teeth is a function of forensic dentistry referred to as bite mark identification. This form of impression identification, also called forensic odontology, is based on the assumption that no two people in the world have front teeth that are identical in thickness, shape, relationship to each other and patterns of wear.

     The process of comparing a bite mark to a known set of teeth is not unlike the identification of latent fingerprint, footwear and tire track impressions. Bite mark wounds are found on victims of murder, rape and child molestation. This type of crime scene evidence is preserved by life-size photography, tooth mark tracings onto transparent sheets and dental casts of the impressions themselves. A suspect might be asked to bite down on a pliable surface for an impression sample, have a cast made of his teeth, or both. Usually, connecting a suspect to a victim through expert bite mark testimony will be enough evidence, by itself, to sustain a criminal conviction.

     The field of bite mark identification exploded in the 1980s, and hundreds, if not thousands of defendants between 1983 and 2002 were sent to prison on the strength of bite mark testimony. Although bite mark identification had been a recognized branch of forensic science since 1970, it was the 1979 trial of serial killer Ted Bundy in south Florida that put this form of identification on the map the way the O. J. Simpson case in the mid-1990s popularized DNA profiling.

     At the peak of bite mark evidence credibility among forensic scientists, detectives, prosecutors and judges, this form of impression identification was put on the level with the matching of fingerprints. However by 2003 forensic scientists were seriously questioning the assumption that bite marks were as unique and identifiable as latent fingerprints.

     Over the years several leaders in the bite mark field oversold the reliability of this form of identification. For example in 1977 Dr. Lowell J. Levine, a forensic dentistry consultant to the New York City Medical Examiner's Office, wrote: "Since every person's teeth are unique in respect to spacing, twisting, turning, shapes, tipping toward the tongue or lips, wear patterns, breakage, fillings, caps, loss and the like, all of which occur in limitless combinations, it is possible for them to leave a pattern which for identification purposes is as good as a fingerprint."

     In 1996 Dr. C. Michael Bowers, a prominent southern California odontologist, was one of the first forensic scientists to raise doubts about the credibility of bite make identification when he wrote: "Physical matching of bite marks is a non-science which was developed with little testing and no published error rate....An opinion is worth nothing unless the supportive data is clearly describable and can be demonstrated in court. How does one weight the importance of a single rotated tooth in a bite mark when the suspect has a similar tooth? The value judgments range widely on the value of this feature. This is not science. Instead, statistical levels of confidence must be included in the process."

     In a bite mark identification exercise Dr. Bowers conducted in a workshop at the 1999 American Academy of Forensic Science conference, 63 percent of the odontologists who participated made an incorrect identification, findings that displeased many in the field when Dr. Bowers published the results of his experiment. In an article published in 2003 in the British Dental Journal, Dr. D. K. Whittaker, a forensic dentistry professor at the University of Wales, explained why bite mark evidence is so difficult to identify, particularly bite marks on skin:

     "Human bites on skin are difficult to interpret because skin is not good 'impression' material. Moreover, victims may struggle and movement will distort the image of the bite. Skin surfaces are not flat and visual distortion may be present, often heightened by photographic distortion caused by inadequate imaging techniques. Human dentitions, whilst possibly being unique in the small nuances of tooth size, shape, angulation and texture may not inflict unique bite marks which can only record gross and not fine detail. If the victim survives, the injury may change due to infection or subsequent healing and if the victim is deceased, putrefaction may introduce distortion."

     Before odontologists in Great Britain can testify in court as bite mark experts they must have made a minimum of twenty such identifications in other cases. In the United States, an odontologist can be certified by the American Board of Forensic Odontology after two bite mark identifications. As a result, being certified in this forensic field in the United States shouldn't carry much weight. (In fact, two of America's most notorious charlatans in the field were both board certified bite mark experts.)

     In 2004, as part of a journalistic series on forensic science, the Chicago Tribune examined 154 state and federal trials involving bite mark identification testimony. In more than a quarter of these cases the prosecution and the defense produced forensic odontologists whose expert opinions were diametrically opposed. If bite mark identification is an exact science practiced by highly qualified experts, this many odontologists should not have been testifying against each other.

The Steven Fortin Murder Case: Conflicting Bite Mark Testimony

     In 1994 police officers found the body of 25-year-old Melissa Padilla in a concrete pipe along Route 1 near Woodbridge, New Jersey. Naked from the waist down, she had been beaten and sexually assaulted. The killer had bitten her on the chin and left breast. Padilla wa abducted the night before from a nearby convenience store in the Avenel section of Woodbridge. The police had no suspects and the investigation quickly died on the vine.

     In April 1995 the state police in Maine contacted the Padilla case investigators with a lead. They had arrested 31-year-old Steven Fortin for the sexual assault of a female state police officer who had been bitten on the chin and left breast. Fortin was also living in Woodbridge at the time of Padilla's murder. Although the suspect denied involvement in the New Jersey homicide, he pleaded guilty in November 1995 to the assault in Maine. The judge sentenced him to 20 years.

     Five years after entering prison in Maine, the authorities in New Jersey put Fortin on trial for the murder of Melissa Padilla. The prosecution's key witness, FBI criminal profiler Robert Hazelwood, connected the defendant to the Padilla murder by noting similarities in its criminal MO to the sexual assault in Maine. The jury in New Jersey on the strength of this testimony found him guilty. In February 2004 the New Jersey Supreme Court overturned the conviction on the grounds it was not supported by sufficient evidence.

     New Jersey prosecutors retried Steven Fortin in 2007. This time they had physical evidence connecting him to the victim. A DNA analyst testified the defendant could not be excluded as the primary source of the saliva recovered from the Marlboro cigarette butt found near Padilla's body. According to this expert, only one out of 3,500 people could be linked to this evidence. Moreover, the defendant could not be excluded as the DNA source of the blood and tissue traces found under the victim's fingernails.

     Dr. Lowell J. Levine, one of the pioneers in the field of crime scene bite mark identification, a forensic odontologist from upstate New York, compared photographs of the victim's bite mark wounds (The photographs did not include a ruler measuring the marks because the photographer didn't recognize the bruises as teeth marks.) with photographs of the defendant's front teeth. Dr. Levine noticed a space between Fortin's lower front incisors that corresponded to a space in the mark on the victim's left breast. Dr. Levine testified that although he could not say to a scientific certainty that the defendant had bitten the victim, he could not exclude him as the biter.

     Dr. Adam Freeman, a forensic dentist from Westport, Connecticut, testified that in his study of 259 bite mark cases, the largest study of its kind, he found only five cases in which the attackers had bitten their victims on the chin and the breast. Dr. Freeman's testimony had helped link the defendant, circumstantially, to the sexual assault in Maine for which he had pleaded guilty.

     Steven Fortin's defense team countered Dr. Levine with another world renowned forensic odontologist, Dr. Norman Sperber, the chief forensic dentist with the California Department of Justice. Dr. Sperber had testified for the defense at the first trial, but the jury had disregarded his testimony. He, like Dr. Levine, had testified for the prosecution in the 1979 trial of serial killer Ted Bundy. Since then, Dr. Sperber had appeared as an expert witness in 215 trials. According to his analysis, Steven Fortin could not have made the bite marks on Melissa Padilla's body. According to Dr. Sperber: "The tracing of his [Fortin's] teeth doesn't even come close to the crime scene bite marks." The forensic odontologist went on to say that bite mark analysis has limitations as a form of crime scene associative evidence. It was not as reliable, he said, as DNA and fingerprint identification. "Skin is a serious limitation for bite mark analysis because it rebounds and is movable," he said. "Bite mark evidence is not a true science."

     On December 4, 2007 the jury of nine men and three women, after deliberating nine hours, found Steven Fortin guilty of first-degree murder and first-degree sexual assault. The judge sentenced him to life plus twenty years. 

     In June 2020, a New Jersey appellate court, in finding other "strong evidence" besides bite marks to connect Steven Fortin to the New Jersey murder, denied his appeal.

The Douglas Prade Murder Case

     At ten-thirty in the morning of Thanksgiving Day 1997 a medical assistant found 41-year-old Dr. Margo Prade slumped behind the wheel of her van in the doctor's office parking lot. The Akron, Ohio physician, shot six times with a handgun at close range, had fought with her murderer. Physical evidence of this struggle included buttons ripped from Dr. Prade's lab coat, a bite mark on her left inner arm and traces of blood and tissue under her fingernails.

     A few months after the murder, Akron police arrested the victim's husband, Douglas Evans Prade. Captain Prade, a 29 year veteran of the Akron Police Department, denied shooting his wife to death. He insisted that at the time of the killing he was in the workout room of the couple's Copley Township condominium complex.

     In 1997 DNA science compared to today was quite primitive. As a result DNA tests of trace evidence from the bite mark and the blood and tissue under the victim's fingernails were inconclusive. DNA analysts were unable to include or exclude Captain Prade as the source of this crime scene evidence.

     Video footage from a security camera at a car dealership next to the murder scene revealed the shadowy figure of a man climbing into Dr. Prade's van at 9:10 in the morning of her death. A hour and a half later the man exited the murder vehicle and was seen driving out of the parking lot in a light-colored car. Homicide detectives never identified this man who could not have been taller than five-nine. The suspect, Captain Prade, a black man, stood over six-foot-three. Had investigators focused their efforts on identifying the man in the surveillance video they may have resolved the case. But detectives had their minds set on the victim's husband and ignored all evidence that pointed in a different direction.

     To make their case against Captain Douglas Prade detectives asked a retired Akron dentist named Dr. Thomas Marshall to compare a photograph of the death scene bite mark to a dental impression  of the suspect's lower front teeth. According to Dr. Marshall, the only person who could have bitten Dr. Prade was her husband. The suspect's known dental impressions, according to the dentist, matched the crime scene evidence perfectly. At the time, before advanced DNA technology exposed bite mark identification analysis as junk science, Dr. Marshall's identification carried great weight.

     In September 1998, following a two-week trial in a Summit county court, the jury after deliberating only four hours found Douglas Prade guilty of murdering his wife. The only evidence the prosecution had pointing to the defendant's guilt was Dr. Thomas Marshall's bite mark identification. Without the dentist's testimony there wouldn't have been enough evidence against Douglas Prade to justify his arrest.

     Following the guilty verdict the defendant stood up, turned to face the courtroom spectators, and said, "I didn't do this. I am an innocent convicted person. God, myself, Margo and the person who killed Margo all know I'm innocent." Common Pleas Judge Mary Spicer sentenced Douglas Prade to life without the chance of parole until he served 26 years. Shortly thereafter the prisoner began serving his sentence at the state prison in Madison, Ohio. At that point he expected to die behind bars.

     In 2004, attorneys with the Jones Day law firm in Akron and the Ohio Innocence Project took up Douglas Prade's case. After years of motions, petitions, reports and hearings an Ohio judge ordered DNA tests of the saliva traces from the bite wound, scrapings from the victim's lab coat and scrapings from under Dr. Prade's fingernails.

     In August 2012 DNA analysis of the crime scene trace evidence revealed that none of the associative evidence came from Douglas Prade. (The DNA work was performed by the DNA Lab Diagnostic Center in Fairfield, Ohio.) Summit County Judge Judy Hunter, on January 29, 2013, ordered the release of the 65-year-old prisoner.

     On March 19, 2014 an Ohio appeals court decided that the new DNA evidence did not prove that Mr, Prade didn't murder his wife. The appellate judge said that Mr. Prade's release from prison was a mistake and that he should be taken back into custody. The morning after that decision Mr. Prade found himself back behind bars.

      In March 2018 the Ohio Supreme Court refused to hear his case.

     Douglas Prade's attorneys began appealing his conviction through the federal appellate court system. After the 9th Circuit Court of Appeals rejected Prade's motion for a new trial the case went to the U.S. Supreme Court. On November 6, 2019, America's highest court refused to hear the appellant's case. This essentially exhausted Douglas Prade's legal remedies.

    Douglas Prade is serving his time at the Lorain Correctional Institution in Lorain, Ohio. The 72-year-old will be eligible for parole in 2025.

     In June 2025 Mr. Prade's first parole request was denied. His next parole hearing is in 2033. 

Bite Mark Evidence on Trial: The William Richards Murder Case

     In 1993, 44-year-old William Richards and his wife Pamela, while building a house near Hesperia, California in the high desert in San Bernardino County, lived in a motor home. Because there were no power lines near the property a generator in a nearby shed provided the electricity. Mr. Richards worked as a swing shift electrical engineer at a manufacturing plant in the town of Corona. His 40-year-old wife had a job as a waitress. The following account of what happened on August 10, 1993 is based on William Richards' statement to the police.

     That night William Richards clocked out of the plant in Corona at 11:03. When he arrived home shortly after midnight he noticed there were no lights on in the trailer. He re-started the generator in the shed, and as he walked toward his front door, stumbled over his wife's half nude body. Someone had smashed the 5-foot-2, 126 pound woman's head with a heavy object. Mr. Richards called 911.

     Deputies from the San Bernardino Sheriff's office arrived at the scene at twelve-thirty that morning. The officers did nothing to protect the crime scene while they waited for the arrival of the homicide detectives. The investigators didn't show up until 3:15, and when they did, decided to wait until daylight before processing the crime scene. In the meantime officers walked around the site and did nothing to keep several dogs off the property. (When they did begin the crime scene investigation the officers realized dogs had kicked dirt on Pamela Richards' body.)

     From the beginning homicide detectives considered William Richards the prime suspect in the murder. Blood spatter patterns suggested the victim had been partially undressed after the bloody attack in an effort to stage a sexual assault.  Investigators found no signs of forced entry into the dwelling and no physical evidence of an intruder such as foreign shoe impressions and tire tracks. (If there had been such evidence it could have been trampled by the police.) Moreover, nothing had been stolen from the trailer. Investigators believed that Pamela Richards had been bludgeoned by a blood-stained steppingstone. The forensic pathologist would find she had also been strangled.

     As for motive detectives believed the suspect, after he learned his wife planned to leave him for another man, killed her in a fit of rage. The fact that Richards and his wife over their twenty-year marriage openly had affairs and already agreed to separate, cast doubt on this motive to kill her. Without a confession or an eyewitness, the San Bernardino County prosecutor had a weak circumstantial case. The fact the crime scene investigation had been bungled also hurt the prosecution's case. Nevertheless, the prosecutor charged Mr. Richards with first-degree murder. Police arrested him on September 3, 1993.

     In July 1994, after the jury voted six to six on the question of William Richards' guilt, the judge declared a mistrial. Just three days into his second trial in October 1994 the judge, due to improper communications with a juror, declared a second mistrial. In January 1995 the jury deadlocked eleven to one for his guilt. This led to a third mistrial.

     The San Bernardino County prosecutor, on his fourth try in July 1997 bolstered the state's case with the testimony of Dr. Norman Sperber, the renowned forensic odontologist (dentist) from San Diego who testified at Ted Bundy's serial murder trial in Florida. Dr. Sperber testified that in his expert opinion the crescent-shaped impression on Pamela Richards' hand was consistent with having been made with the defendant's front teeth. The odontologist said that only two percent of the U.S. population could have made this crime scene bite mark.

     To counter Dr. Sperber's testimony the defense presented another respected forensic dentist, Dr. Gregory Golden, the Chief Forensic Odontologist of San Bernardino County. Dr. Golden testified that the photograph of the victim's bite mark was such poor quality he couldn't make a conclusive determination in the case. When pressed by the prosecutor on cross-examination Dr. Golden said that he could not eliminate the defendant as the maker of the crime scene bite mark.

     Based on the new bite mark evidence, the jury in Richards' fourth trial found him guilty of first-degree murder. The judge sentenced him to 25 years to life. The convicted man continued to maintain his innocence.

     In 2000 lawyers with the California Innocence Project entered the case on William Richards' behalf. A re-evaluation of the forensic evidence in the murder case led to a petition before a San Bernardino County judge to overturn Richards' murder conviction. The hearing on this motion took place in 2009 before Judge Brian McCarville.

     Since Mr. Richards' fourth trial new technology had made it possible to sharpen the photographic image of the crime scene bite mark. Dr. Norman Sperber took the stand and declared that after analyzing the enhanced photograph it was his expert opinion the questioned bite mark had not been made by Mr. Richards. Two other forensic dentists agreed with this analysis, and a third testified that he could not render a conclusive opinion either way.

     A DNA expert testified that the bloody steppingstone contained DNA evidence that did not come from the defendant. A forensic hair and fiber identification expert testified that a 2-centimeter follicle taken from under one of the victim's fingernails did not match samples taken from her husband.

     Judge McCarville, based on the bite mark, DNA and hair follicle testimony overturned William Richards' murder conviction.

     The San Bernardino County prosecutor appealed Judge McCarville's ruling to the California Supreme Court. On December 3, 2012, in a 4-3 decision, the state's highest court reinstated Richards' murder conviction. According to the majority justices the forensic evidence presented at the 2009 hearing did not prove the convicted man's innocence. (Once convicted, the burden of proving innocence shifts to the defendant.) These justices did not believe the forensic dentists had completely ruled out Richards as the source of the crime scene bite mark.

     The dissenting judges did not agree with this interpretation of the new bite mark testimony. As these three justices saw it, three of the four odontologists, including Dr. Norman Sperber, stated the convicted man was not the source of this crime scene evidence. Since it had been this evidence that finally led to Richards' murder conviction, its absence supported the position that the state had not carried its burden of proving this man's guilt beyond a reasonable doubt.

     In September 2014 a new law went into effect in California that would make it easier for William Richards' attorneys to have his conviction overturned. Under this legislation, whenever an expert witness changed his or her opinion, as Dr. Sperber did in the Richards case, the initial testimony would be classified, by law, as false evidence. If that evidence played a vital role in the guilty verdict the expert's repudiation was grounds for overturning the conviction.

     Citing the new law Mr. Richards' attorneys asked the California State Supreme Court to reconsider the case and throw out the murder conviction.

     On May 27, 2016 the California Supreme Court overturned William Richard's 1997 first-degree murder conviction. Following this decision the San Bernardino District Attorney decided not to retry the case.