Tag Archives: forensic testimony

Tuesday’s Quick Clicks…

Another Texas Exoneration Calls Bite Mark Evidence Into Question

From: Texas Monthly

Steven Chaney became the twenty-sixth person to be wrongly convicted or indicted based on bite mark evidence. The two dental experts who testified against him have also testified in numerous other cases—and they’ve been wrong before.

By Michael Hall

After serving 28 years in prison, Steven Chaney walked away a free man last Monday when a Dallas judge overturned his 1987 murder conviction. The clincher that sent Chaney to prison nearly three decades ago? Bite mark testimony, given at his trial by two forensic odontologists. The clincher that secured his freedom? Discredited bite mark testimony.

The outcome of Chaney’s case is yet another notable strike against the controversial practice of using bite marks to secure convictions. For decades, testimony from forensic dentists—who inspect the injuries of victims and attempt to match them to the dental patterns of alleged perpetrators—has been admissible in court. Often, this testimony is the prosecutor’s only physical evidence.

Chaney was on trial for the murder of John Sweek, a drug dealer found stabbed to death on his kitchen floor. Chaney, a construction worker, had been one of Sweek’s customers. During the trial, Homer Campbell, a forensic dentist from Albuquerque, told the court that there was a “reasonable dental certainty” that the bite marks on Sweek’s arm came from Chaney. Jim Hales, chief dental consultant for the Dallas County Medical Examiner’s Office, piled on with an alarming statistic: that there was a “one to a million chance” someone other than Chaney was the biter. Even though Chaney had nine alibi witnesses, the jury placed considerable stock in the word of these experts. One juror, when asked why he voted for Chaney’s guilt, said, “The bite mark.”

But now, in an affidavit filed with the court, Hales has admitted what critics of bite mark evidence have been saying for years: even an expert can’t reliably match bite marks to teeth.

Conclusions that a particular individual is the biter and their dentition is a match when you are dealing with an open population are now understood to be scientifically unsound. Under today’s scientific standards, I would not, and could not, testify to a reasonable medical/dental certainty as I testified at the time of trial nor could I testify that there was a ‘one to a million’ chance that anyone other than Mr. Chaney was the source off the bite mark.

Chaney’s lawyers—Julie Lesser, with the Dallas County Public Defender’s Office, and Barry Scheck of the Innocence Project—challenged the conviction, citing Texas’s junk science law, passed in 2013, which says that a conviction can be attacked in a writ of habeas corpus if there is new science that contradicts the science that was used at trial.

The truth is, there was never any conclusive data or rigorous studies to back up bite mark evidence, which has been under fire from scientists and defense lawyers ever since it was first allowed in court in 1974. Tests of bite mark evidence reliability have found error rates between 12 and 64 percent, but since no court ever ruled against its admissibility, it was allowed.

Bite marks are nothing like DNA profiles.

Forensic odontologists sometimes can’t even agree on whether marks found on – skin—a malleable, inconstant medium—came from teeth or not. The first official red flag about bite mark evidence came in 2009 when a report from the National Academy of Sciences said, “The scientific basis is insufficient to conclude that bite mark comparisons can result in a conclusive match.” Around that time a husband and wife team of researchers at SUNY Buffalo began doing research on bite marks using cadavers, and after more than a dozen studies, they found that “statements of dental uniqueness with respect to bitemark analysis in an open population are unsupportable.” In other words, bite marks are nothing like DNA profiles—and there are certainly no statistics to back up accurate comparisons between sets of teeth, like Hales did when he said there was a “one to a million chance” anyone but Chaney was the biter.

It was significant that Dallas County DA Susan Hawk concluded that “the bite mark evidence that was critical to [Chaney’s] conviction has been discredited”—he is now the twenty-sixth person to have been wrongly convicted or indicted based on bite mark testimony—but county prosecutors knew about his case for months. All summer long the Texas Forensic Science Commission—which for the past five years has been blazing a trail of state-wide criminal justice reforms via numerous investigations of labs and forensic disciplines—has been looking into bite marks after a complaint was filed by Chaney’s lawyers, who asked the commission to “exercise its statutory mandate to investigate and report on ‘the integrity and reliability’ of bite mark evidence.” The FSC has already held one meeting to look into bite marks—last month in Dallas—and Chaney’s name came up often. His name will come up again when the FSC convenes again next month in Fort Worth.

One of the things Chaney’s lawyers asked the FSC to do is go back and vet cases where bite mark testimony was used in Texas in the same way the FSC has been re-investigating old hair microscopy cases. When it does so, the commission will find other troublesome Texas cases, including three that Campbell (now deceased) and/or Hales handled at the same time as Chaney’s.

One of those cases involved two men convicted for the rape and murder of Juanita White in Waco in 1986. When investigators found what they believed to be bite marks on White’s body, they took a dental mold of a suspect named Calvin Washington and drove it to Dallas for Hales to inspect. His conclusion? Washington’s teeth matched the wounds on White’s body. But the story didn’t end there. Investigators began to suspect Washington had an accomplice, a man named Joe Sidney Williams, and they made a mold of his teeth too. This mold—along with Washington’s mold and White’s autopsy photos—was sent to Campbell, who saw things differently than Hales: Williams was the biter, not Washington. Prosecutors chose to go with Campbell’s identification, not Hales’s, and in August 1987 Williams went on trial. The only physical evidence were the bite marks. Campbell identified four of them on White’s body and said Williams’s teeth were consistent with an injury on her hip. “The research states that there are no two people that have the same position [of their teeth],” Campbell testified, though no such research has ever been done. Williams was found guilty, as was Washington in a later trial where almost the same evidence was presented.

But both Campbell and Hales were wrong, a fact not found out until 2000, when the semen in the rape kit was compared to the DNA profile of another man. It matched the new suspect and Washington was freed. (Williams had been freed in June 1993 because testimony from a jailhouse informant had been ruled inadmissible.) The two men served a total of 19 years in prison for a murder they had nothing to do with—all based on bogus bite mark testimony.

The third case is even more troubling because it involved an execution. The defendant’s name was David Spence, and he was, oddly enough, Juanita White’s son. (For more on this labyrinthian case read “The Murders at the Lake.”) Spence was convicted in two trials, in 1984 and 1985, of the murders of three Waco teens and given the death penalty. The only physical evidence against him: bite marks on the bodies of two of the victims. The expert who testified: Homer Campbell. Spence, Campbell said, was “the only individual” to a “reasonable medical and dental certainty” who could have bitten the women. According to jurors, Campbell’s words were powerful. “We had life-size pictures of the marks and a cast of [Spence’s] teeth brought into the jury room,” remembered one juror afterward. “The testimony—‘everyone’s bite mark is different, like a fingerprint’—was very convincing.”

Spence’s appellate lawyers tried to attack Campbell’s methods with other forensic odontologists. One, Thomas Krauss, a former president of the American Board of Forensic Odontology (ABFO), said Campbell’s methodology was “well outside the mainstream.” Krauss helped the lawyers set up a blind panel of five odontologists to analyze the autopsy photos and vet Campbell’s work by comparing the marks with dental molds from Spence and four other subjects. The results were astonishing. Though the five experts identified several patterns that were possibly bite marks, they couldn’t say much more. One of them said the photos were too poor in quality to compare to the molds. A second wrote that the marks were “more likely than not made by insects or artifacts.” A third thought that some of the marks were probably bite marks, but he couldn’t match any of the molds to them. Two of the experts did indeed match one of the marks to one of the molds, but it was not Spence’s. It belonged to a housewife from Phillipsburg, Kansas. Unfortunately for Spence, the study wasn’t completed until after the deadline for Spence’s writ. He was eventually executed, despite numerous questions about his guilt—the biggest coming from the fact that the only physical evidence against him came from Campbell.

Campbell made at least one other embarrassing mistake that we know of. In 1984, a few years before he testified against Spence and Chaney, he was asked by a lieutenant in the sheriff’s department in Coconino County, Arizona, for help in identifying the body of a young woman found alongside I-40 near Flagstaff. The lieutenant had a hunch the girl was a missing runaway from Jacksonville, Florida, named Melody Cutlip, who had left home in 1981. Campbell compared the corpse’s teeth with those in a photo of Cutlip that he enlarged. “They matched exactly,” he told the Ocala Star-Banner. Cutlip’s family was notified and the corpse was buried in a Williams, Arizona, cemetery under a headstone with her name. In 1986, Cutlip contacted her mother. She was alive. Campbell was wrong.

A review of old bite mark cases will almost certainly reveal more false identifications, simply because of the nature of the way experts thought and testified. As Hales said in his affidavit in Chaney’s case:

At the time of the trial in December 1987 both the ABFO guidelines and the scientific field of Forensic Odontology supported use of the terms match and biter to relate a suspected person to a bite mark and it was permissible for experts to testify to a reasonable degree of medical/dental certainty that an individual was the biter in a case.

And indeed, if you go back and look at old cases, the word “match” is constantly used by experts, dating back to that very first 1974 case (“The bite mark matches the teeth reproduced in the model”). If experts didn’t say “match,” they said words that meant the same thing: “no question in my mind” (the defendant bit the victim); “it could be no one but [the defendant] that bit this girl’s arm.” Sometimes, as Hales did in Chaney’s trial, they would go further and use statistics, even though no studies had ever been done. Campbell did it in a 1977 Arizona case, when he testified that marks found on a murder victim’s breasts and a model he’d made of defendant’s teeth were “consistent,” which he then quantified by saying, “The probability factor of two sets of teeth being identical in a case similar to this is, approximately, eight in one million, or one in 125,000 people.”

Statements like these were, in Hales’s own contemporary words, “scientifically unsound”—opinions from well-intentioned experts with little to guide them but their own eyes and their own experience. (We reached out to Hales, who declined to comment for this article.) Campbell himself acknowledged the basic problem with bite mark analysis during the Joe Sidney Williams trial in 1987, when he was asked about its inherent subjectivity. “It is subjective,” he said. “I’ll admit it.”

– See more at: http://www.texasmonthly.com/articles/another-texas-exoneration-calls-bite-mark-evidence-into-question/#sthash.oOh4ghum.dpuf

Tuesday’s Quick Clicks…

Wednesday’s Quick Clicks…

Wednesday’s Quick Clicks…

Modern Forensics vs. Good Old-Fashioned Texas Justice: The Trials of Ed Graf

From: Slate.com

By Jeremy Stahl

Ed Graf was a bad employee. While working at Community Bank in Texas in the 1980s, he allegedly embezzled from his employer, eventually paying the bank more than $75,000 to avoid prosecution. Ed Graf was a bad husband. His ex-wife, Clare, would call him “the most possessive person I’ve ever known.” Clare’s best friend, Carol Schafer, said her husband, Earl, saw Graf having sex with another woman the night of Graf’s bachelor party. Ed Graf was, according to Clare and her family, a bad father. Two of Clare’s family members accused him of beating his adopted stepsons, Joby and Jason, with a board and belt.

In 1988, a Texas jury found that Ed Graf was also a murderer. Prosecutors argued that two years earlier, on Aug. 26, 1986, Graf had knocked out Joby, 9, and Jason, 8, and placed the boys in the back of their family shed. Graf had then spread gasoline, locked the shed, and set the boys ablaze. The two inseparable, athletic, blond-haired brothers died of smoke inhalation and severe burns in the backyard of their home. The address was 505 Angel Fire Drive.

On the day of the fire, Graf broke the news to his wife, telling Clare that both boys had been lost in the blaze. But Graf had been informed that the body of one child had been found, not both. It was one of many pieces of circumstantial evidence that prosecutors would pile up to present Graf as a calculating, greedy, and callous monster who murdered the children in a desperate attempt to keep his troubled marriage together.

Other small clues seemed to point to Graf’s guilt. Multiple witnesses say they saw a gasoline container on the porch, not far from the kids’ bikes. Graf also acted strangely after the fire. He suggested the boys be buried in one coffin, according to multiple witnesses. He didn’t offer his wife consolation, or apologize that they died in his care. A few weeks after the fire, Graf returned about $50 worth of Joby and Jason’s new school clothes that he had previously insisted they keep the tags on. There was more of what others saw as signs of foreknowledge. The normally meticulous Graf, who was said to keep lists for everything, neglected to buy the boys’ cereal or fill Jason’s Dimetapp prescription the week of their deaths.

In addition to the circumstantial evidence, prosecutors were able to present motive. Weeks before the fire, Graf had taken out $100,000 worth of combined life insurance on the boys if they were to die in an accident. The policies had been mailed out the day before the fire.

The real motive, prosecutors argued, was to get the boys—a source of regular bickering between Graf and his wife—out of their lives. His wife testified that shortly before the fire, she had threatened to leave him over his strict discipline of Joby and Jason, sons from a previous marriage, and to take their newborn third son, Edward III, with her.

The case was still largely circumstantial, though. The thing that likely clinched Graf’s conviction was the scientific testimony of a pair of forensic examiners. Joseph Porter, an investigator with the State Fire Marshal’s Office, testified that, based on his analysis of photos of the remains of the scene, the door of the shed must have been locked from the outside at the time of the fire, which would indicate foul play. He also said there were obvious charring patterns on the floor of the shed left by an accelerant. “The fire was definitely incendiary,” Porter declared. The prosecution’s other expert, a top fire investigator from New York known for his report on the Osage Avenue fire, a notorious fire set by Philadelphia officials that destroyed a primarily black neighborhood, was brought in to testify that there was “no doubt” that this was arson.

If the fire was intentionally set, then Graf was the only suspect with means, motives, and opportunity. Even if there was no direct evidence connecting him to the crime, the circumstantial evidence and the word of two arson experts was enough. The jury deliberated for four hours before pronouncing him guilty of capital murder.

The jurors then had to decide the punishment. The district attorney, Vic Feazell, said that the “facts of the case cry out” for the death penalty—two boys burned alive, murdered by a trusted parent.

Defense attorney Charles McDonald gave an impassioned plea that the jurors had convicted an innocent man and would make the injustice irreversible if they chose execution over life in prison. “I’m asking for this man’s life because if you did make a mistake there’s going to be some folks, somewhere down the line, it may be years … but maybe the mistake can be corrected,” McDonald argued. “If you take this man’s life, there ain’t no way to ever correct it.” The jurors must have found this argument compelling, because they spared Ed Graf’s life.

Twenty-five years later, the Texas Court of Criminal Appeals decided that a mistake had, in fact, been made. The investigators who testified the fire was arson used what in the years since has been discredited as junk science. A state review panel set up to examine bad forensic science in arson cases said that the evidence did not point to an incendiary fire. A top fire scientist in the field went one step further: The way the boys had died, from carbon monoxide inhalation rather than burns, proved the fire couldn’t have been set by Graf spreading an accelerant, and was thus likely accidental. The defense’s theory was that the boys, who multiple witnesses said had a history of playing with matches and cigarettes, had set the fire themselves, attempted to put it out, and been quickly overcome by carbon monoxide poisoning.

The reason Ed Graf’s case was reviewed a quarter of a century after he barely escaped the death chamber was because of one man: Cameron Todd Willingham. He was convicted, based on similarly faulty scientific evidence and the testimony of a jailhouse informant who later recanted and said he was bribed, of murdering his three children by setting their home on fire two days before Christmas in 1991. Willingham was executed 11 years ago. Only after Willingham’s death was it revealed publicly that the forensic evidence used to convict him was bunk. In 2009, the New Yorker’s David Grann wrote a groundbreaking article describing Texas’ flawed case against Willingham. The story sparked a national uproar over forensic science and the death penalty.

Then Texas did something surprising. While the state has not budged in its use of the death penalty—just last year topping 500 executions since the state brought back capital punishment in 1982—it has reinvented itself as a leader in arson science and investigation. A new fire marshal, Chris Connealy, revamped the state’s training and investigative standards. He also set up a panel comprised of some of the top fire scientists in the country to reconsider old cases that had been improperly handled by the original investigators.

Graf’s case was one of the first up for review, and it was determined that the original investigators had made critical mistakes. The Texas Court of Criminal Appeals agreed, overturning the original conviction.

Graf’s successful appeal proved that Texas was serious about correcting past forensic errors, but his story was far from over. Prosecutors in Waco were not convinced of his innocence. They felt that they had enough evidence to reconvict. Just because the forensic science was flawed didn’t change the fact that, in the eyes of prosecutors, Ed Graf was a bad employee, a bad husband, and a bad father—a man capable of murdering his adopted children.

So there was a new trial, and Graf became the first man in Texas to be retried for an arson murder that had been overturned thanks to advances in fire science. His new trial set up a clash between modern forensics and the old way of pursuing criminal justice in Texas, a state where prosecutors have often gone to questionable lengths to win convictions against high profile murder defendants—including multiple men later proved innocent.

Prosecutors in Graf’s retrial spared no effort to win a second conviction in a strange and dramatic retrial last October. The trial’s surreal and unforeseeable conclusion would have a profound impact not just on the fate of Ed Graf, but on the lives of other prisoners who in the wake of the Willingham case held out new hope that their convictions might be overturned and their innocence acknowledged…

Continue reading on Slate.com at Chapter 2 New Memories

Will Florida governor seek review of cases involving discredited witness?

Governor Rick Scott has formally apologized “on behalf of the state of Florida” for the 27 years William Dillon spent in prison for a crime he did not commit.  He has also signed a claims bill of $1.35 million.  It took another three years of Dillon’s life to navigate the process of getting compensation from the state. But Dillon remains unsettled over the thought of others wrongfully convicted by the now deceased John Preston, Brevard County authorities’ go-to witness whose German shepherd had quite a nose. Preston claimed he could pick up a scent in the middle of a lake Continue reading