Please see our “Did You Know?” section toward the end of this issue.
Topic: Making an impression- Bite-mark study could bolster use as evidence
In the news, ‘a congressionally mandated committee, convened under the auspices of the National Academy of Sciences, is examining the range of challenges facing practitioners of forensic science”. The goal is to highlight “what has become a dire problem at all levels of law enforcement and by recommending some badly needed standards for a fast-growing field of science.”
The states of Florida, Kentucky, New York, Ohio and Washington have been selected to participate in the Improving Forensic DNA Policy Project. The goal of this project is to help states ensure that they are using DNA to its full extent as a tool to promote public safety.
In Colorado Governor Bill Ritter and the Colorado District Attorney’s Council announced the collaborative formation of a working group to examine how DNA evidence is collected and preserved in Colorado.
In the same State, a case that would involve familial searching is raising controversy. The prosecutor in the case wants to use the close DNA match to track down a rapist. While familial searching has helped solve a number of cases, some feel that this “practice promotes the notion of guilt by association by placing relatives of convicts under "what amounts to genetic surveillance."
And in San Diego, California “police have added DNA evidence collection to their protocol for burglary investigations, just as they do for homicides and sexual assaults, and it's paying off. According to a study by Patrick O'Donnell, supervisor of the crime lab's DNA unit, about 75 percent of burglary cases where biological evidence exists are producing so-called cold hits – and arrests – from a DNA database. Does it make sense to spend $2,000 to solve a $400 burglary?...The answer may be yes, Gialamas said, if it results in catching a crook who is responsible for other crimes or stopping a crook from moving to more serious crimes.”
Following these stories we are including a number of new and ongoing cases involving the use of DNA evidence.
Justice Delayed
Overburdened crime labs are undermining law enforcement
When it comes to determining budget priorities for law enforcement, DNA scientists and drug analysis technology are no match for patrol cars and police on the beat. That helps explain why the resources available for crime labs have not kept pace with the demands of police departments and prosecutors. Long backlogs for analysis of DNA, fingerprints, fibers, drugs and other types of forensic evidence are the rule at publicly funded crime labs around the country. Imagine your doctor ordering a blood test and saying you'll have the results in six months to a year -- that's the sort of time frame that police and prosecutors in some places face routinely.
The backlogs have contributed to occasional miscarriages of justice, including probably guilty suspects who walk free and others, wrongly charged, who languish in jail for want of timely forensic analysis. Such cases grab the headlines, leaving little room on the public's agenda for more prosaic problems such as crime labs so overburdened with work and short on staff that they accept only evidence in homicide and rape cases while refusing work related to lesser crimes.
One obvious problem is inadequate state and federal spending. The $100 million-plus appropriated annually by Congress in recent years to expand the DNA testing capacity at crime labs has helped, but not enough to prevent huge backups in many places. As for other, less glamorous types of forensic testing, which represent 90 percent or more of the work performed by most labs, they have received a relative pittance from Washington. With a few exceptions, state and local governments have not taken up the slack. The lack of funding has contributed to severe shortages of qualified staff.
But the problems plaguing crime labs are broader and deeper than a shortage of cash or what's popularly known as "the CSI effect" -- the wildly inflated expectations of jurors who expect real-life investigations to be as crisply resolved and as subject to scientific certainty as the television variety. A congressionally mandated committee, convened under the auspices of the National Academy of Sciences, is examining the range of challenges facing practitioners of forensic science, including inadequate training and education of technicians; flawed testing techniques; insufficiently rigorous standards of evidence analysis; spotty proficiency testing; and erratic accreditation regimens. The committee, chaired by Harry T. Edwards, former chief judge of the U.S. Court of Appeals for the D.C. Circuit, and Constantine Gatsonis, director of Brown University's Center for Statistical Sciences, started work this year and is expected to issue its report next summer. It could perform a real service, both by highlighting what has become a dire problem at all levels of law enforcement and by recommending some badly needed standards for a fast-growing field of science.
Source: http://www.dnalabsinternational.com/email_newsletter/vol_50_aug_07/vol50_ref01.html
Improving Forensic DNA Policy Project
The NGA Center for Best Practices, with support from the National Institute of Justice (NIJ), is working to assist states in improving how forensic DNA is used to promote public safety. DNA can provide an unparalleled degree of certainty in solving crimes, identifying criminals, and identifying victims of violent crime. However, its full potential as a crime-fighting and crime-solving tool remains underutilized.
Massive backlogs of unanalyzed DNA crime scene evidence and convicted offender samples can hinder closing unsolved and cold cases. DNA is not widely collected from evidence from high-volume crimes, such as burglary, despite research showing these individuals are also committing violent crimes. Finally, most states do not require taking of DNA samples in cases involving unidentified human remains that could potentially assist in closing nearly 110,000 active missing person cases in the National Crime Information Center's (NCIC's) Missing Person File. Complicating matters is the fact that advances in state DNA programs are at risk because the federal funds that helped support their expansion and operation are due to sunset in 2009.
Focus of Center Activities
The goal of the Improving Forensic DNA Policy Project is to help states ensure that they are using DNA to its full extent as a tool to promote public safety. The project will assist governors and other state policymakers in developing strategies to improve the use of and funding for forensic DNA. The project focuses on many areas of DNA policy including training, coping with increasing demand, developing alternative funding sources, and finding cost savings.
Through the project, states will have the opportunity to work with peers from other states as well as a national faculty of researchers, representatives from NIJ, and other experts over the course of the year to identify solutions to these challenges.
Five states were selected through a competitive process to participate in the project. Activities include participation in a learning lab on forensic DNA; participation in an in-state policy workshop for the state team; and the provision of ongoing as-needed technical assistance.
The teams will work together to evaluate the state's current use and funding of forensic DNA and will begin got develop a strategic response that ensures maximum public safety benefit and sustainability.
The five states that have been selected to participate in the project are:
- Florida
- Kentucky
- New York
- Ohio
- Washington
Source: http://www.dnalabsinternational.com/email_newsletter/vol_50_aug_07/vol50_ref02.html
Colorado Governor Ritter And District Attorneys Announce Working Group On DNA Evidence
Colorado Governor Bill Ritter and the Colorado District Attorney’s Council today announced the collaborative formation of a working group to examine how DNA evidence is collected and preserved in Colorado.
An independent team of experts and stakeholders will come together to study DNA collection, preservation and analysis practices in Colorado. The working group also will examine best practices nationally to see if they need to be implemented in Colorado.
The Governor, who will appoint the group’s chairperson, and the District Attorney’s Council said they expect the team will present its finding and possible recommendations this fall. The group will include law enforcement officials, the criminal defense bar and legislators.
“As Denver’s former District Attorney, I am pleased to join with the CDAC to assess our current system and identify areas that may need refinement,” Gov. Ritter said. “It’s extremely important that the people of Colorado feel confident in their criminal justice system and how that system handles DNA evidence.”
“DNA evidence is one of the best tools for exposing the guilty and protecting the innocent,” said Don Quick, Adams County District Attorney and president of the CDAC. “Our DNA collection and preservation methods must be top notch. This working group will examine what Colorado already does well, and make suggestions on what we can do better.”
“I’m pleased that all the stakeholders want to come to the table and examine how to best preserve DNA evidence in Colorado,” said state Rep. Cheri Jahn. “I look forward to meeting with the experts in the DNA field and hearing from the public about their experiences. We will focus on creating a process for the preservation of DNA evidence, to give closure to the victims of heinous crimes, to correct injustice if there has been a wrongful conviction, and to use DNA technology to protect our citizens and all victims of crime.”
Source: http://www.dnalabsinternational.com/email_newsletter/vol_50_aug_07/vol50_ref03.html
DNA 'near matches' spur privacy fight
Denver's district attorney wants the DNA profile and identity of a California felon who is a close but not perfect match to the man who committed an unsolved Denver rape, in the hope that the two are related.
The prosecutor, Mitchell Morrissey, wants to use the California man's personal information to track the unknown rapist. Their genetic similarities, he says, suggests the California felon and the suspect are close relatives.
But California Attorney General Edmund "Jerry" Brown is refusing to release the information, citing a need to protect the privacy of the California felon and the integrity of California's database of criminal DNA. Reporting a DNA near-match, said Brown spokesman Gareth
Lacy, would be "outside the boundaries" of court opinions that authorize DNA database searching and could prompt a lawsuit.
The standoff between the two agencies appears to be the first but likely not the last such clash over a new DNA technique called "familial searching," says Angelo Della Manna, chief DNA analyst for the state of Alabama and an adviser to the FBI on DNA policy.
"At some point you ask yourself as a scientist not only 'what can the science do?' but 'what are we comfortable with it doing?'" Della Manna said. "We're reaching that point now."
Since 1990, the FBI has maintained a computer network designed to solve rapes, murders and other crimes by matching the DNA profiles of convicts and some arrestees with genetic material found at crime scenes. Each state maintains its own database. They are linked by a computer system maintained by the FBI.
Beginning last July, the FBI has permitted but not required states to share information not only in perfect matches but in cases such as the Denver rape in which DNA similarities suggest that the suspect is a relative.
Supporters see obvious advantage for familial searching. The United Kingdom has used such near-matches since 2002; police there have resolved 15 murder, rape and other cases by tracing the perpetrator through a relative's genetic profile. In Science magazine last year, genetics scholars Frederick Bieber, Charles Brenner and David Lazer projected that familial searching could produce 20% to 40% more "useful leads" if used by American police and prosecutors.
The FBI has used the technique to match DNA from a missing child's parent to unidentified remains held on a national database.
But detractors, such as Tufts University urban studies professor Sheldon Krimsky, say the practice promotes the notion of guilt by association by placing relatives of convicts under "what amounts to genetic surveillance." Because unrelated persons sometimes share genetic similarities, near-match searches can bring back the profiles of dozens of non-relatives, Krimsky says.
Additional genetic testing can keep familial searches focused on a few targets, Morrissey says. Unlike California, he says, Oregon and Arizona have agreed to share information on felons whose DNA was a near-match to suspects in different Denver rapes. When additional testing showed the felons and the unknown rapists were not brothers, the searches were dropped.
"These are cases with no leads, that literally are at a dead end," Morrissey says.
Lacy, the California attorney general's spokesman, says his office will "review and evaluate" its policy against familial searching but is unlikely to change soon.
Debbie Shaw, a rape victim's liaison for the Duncanville, Texas, police department who has worked on DNA cases, says that is "not nearly good enough. Privacy is fine, but what about the rape victim?"
Source: http://www.dnalabsinternational.com/email_newsletter/vol_50_aug_07/vol50_ref04.html
Officers at a crime scene now collect DNA evidence
SAN DIEGO – Saylor Wright's Ocean Beach house was cleaned out and trashed.
Burglars ripped her television off a wall, stole clothing, lamps, bedding and silverware. Then they downed a cocktail in her kitchen before hauling their loot out the front door.
Two years have passed, and police are no closer to solving the daytime break-in or recovering Wright's belongings. It's an all-too-familiar experience for frustrated and traumatized burglary victims.
“Very personal items, like my jewelry, are what I miss the most,” said Wright, 53, a hair stylist. “They took what amounted to the journal of my life.”
There may be hope for crime victims such as Wright with more arrests and more cherished possessions returned.
San Diego police have added DNA evidence collection to their protocol for burglary investigations, just as they do for homicides and sexual assaults, and it's paying off.
“We are getting some startling results,” said police Chief William Lansdowne, whose officers are gathering biological evidence such as blood, saliva and hairs. The department's forensic specialists from the crime lab take over from there.
About 7,000 burglaries are reported each year in San Diego. That includes businesses, homes and cars. The most recent statistics for 2007 show an 11 percent increase over last year.
Police have been slowly incorporating DNA gathering in commercial and residential burglary investigations for several years.
'Cold hits' seen
According to a study by Patrick O'Donnell, supervisor of the crime lab's DNA unit, about 75 percent of burglary cases where biological evidence exists are producing so-called cold hits – and arrests – from a DNA database.
In 2005, the crime lab used DNA to get suspect information in 21 burglaries, O'Donnell said. In 2006, the number climbed to 98.
This year, projections are that 200 burglaries will net hits from the DNA database. A federal grant to hire more crime lab personnel and to train officers in evidence collection will make the increase possible, O'Donnell said.
The hits from CODIS – Combined DNA Index System – occur by two means.
“Most hits result from a match between the DNA profile of evidence in the database,” O'Donnell said. “This type of hit identifies the perpetrator of the crime.”
A second hit results when the DNA profile of biological evidence – blood, semen, saliva – at an unsolved crime scene matches evidence from a second unsolved crime, O'Donnell said.
In this case, the identity of the perpetrator is not known, but the crimes are now linked to one person.
Association of multiple crimes might provide important investigative information to help solve the cases, O'Donnell said.
With an increase in lab technicians and lab space, more burglars could be caught using DNA, said Mike Grubb, crime laboratory manager.
“Added resources – people and space – could help us solve a lot more of these cases,” Grubb said.
That's important, considering burglary leads the list of crimes on the increase in the city.
Why?
“It may be that we feel safe in our homes because overall crime continues down in the city,” police Sgt. Robert Carroll said. “So we leave our doors and windows open, especially in the summer when it's hot, and we become more vulnerable.”
Trail begins with call
In the field, the trail that leads to DNA starts with the 911 call to report a burglary.
Officers are dispatched after a break-in is discovered. Such was the case last month when burglars entered a Scripps Ranch house through an open door. They took $100,000 in furnishings and jewelry, all while a resident was asleep in an upstairs bedroom.
“I guess I'm lucky I didn't get hurt – or worse,” the shocked resident told police. “But they took everything of value.”
Officers Chuck De La Cruz and Shannah Kanooa were the first officers to arrive at the noontime crime scene.
The officers, who are trained as field evidence technicians, scanned for DNA.
“We may find it at the point the burglars entered, maybe blood on broken glass, cups or cans for saliva, cigarette butts, hairs,” De La Cruz said.
In addition, Kanooa checks for more traditional evidence, such as fingerprints.
Help from bathroom
A favorite collection spot for DNA comes in the bathroom, where burglars often use the toilet and don't flush.
“Fingerprints, shoe prints and tool marks have long been the bread and butter of burglary crimes – that's what everyone looks for,” said Dean Gialamas, director of forensic sciences for the Orange County Sheriff's Department and a member of the National Institute of Justice working group on DNA forensics.
“We now are extending investigations one more notch to include DNA,” Gialamas said. “This is another piece of forensic science that could answer a lot of questions in lesser crimes.”
Gialamas said there is a cost-benefit component to using DNA to solve crimes such as burglaries.
Does it make sense to spend $2,000 to solve a $400 burglary?
The answer may be yes, Gialamas said, if it results in catching a crook who is responsible for other crimes or stopping a crook from moving to more serious crimes.
Gialamas has no doubt that DNA can lead to more arrests, especially in San Diego.
“The San Diego police crime lab long has been recognized as a leader in DNA,” he said.
All this is little comfort to Saylor Wright, whose Ocean Beach burglary occurred before police began a major push to collect DNA from break-ins.
“I know DNA was left behind by the burglars,” Wright said. “They had a drink in my kitchen.”
Source: http://www.dnalabsinternational.com/email_newsletter/vol_50_aug_07/vol50_ref05.html
New and ongoing cases involving the use of DNA evidence include:
California - A national forensic expert calls the newest round of DNA testing in the 25-year-old murder conviction of Wayne Williams "another nail in his coffin" that reinforces the credibility of the jury's 1982 guilty verdict against Williams.
Recently completed tests of eight human hairs recovered in 1981 from the body of one of the slaying victims represented Williams' last chance to secure new evidence that might have discredited forensic links tying him to 12 slaying victims at his 1982 murder trial. The Fulton County district attorney released the report of the DNA test results Wednesday.
Combined with previously released DNA tests of animal hair taken from the bodies of the victims that were compared with hairs from Williams' dog and an independent examination of forensic fiber evidence made last year at the request of the Daily Report, the latest DNA tests strongly suggest that the jury in the Williams case got it right.
For more on this story, please go to:
Source: http://www.dnalabsinternational.com/email_newsletter/vol_50_aug_07/vol50_ref06.html
New York - Before an arrest was made in the Phoenix Baseline Killer case, investigators had a list of 75 possible suspects and they had DNA profiles of 29 of them. When DNA collected in a Sept. 20, 2005 sexual assault matched one of those profiles, it belonged to Mark Goudeau, a jury was told last week.
Forensic specialist Lorraine Heath said her analysis of DNA found on one of two sisters who had been sexually assaulted led to the arrest of Goudeau two weeks after she made the match.
Heath told the jury that the chances of the DNA found on the left breasts of one of the victims belonging to someone other than Goudeau was one in 380 trillion.
Goudeau is on trial for sexual assault, kidnapping and other crimes related to the 2005 case. Goudeau, 42, faces 74 other criminal counts including nine murders. A trial for those crimes has not yet been scheduled.
Source: http://www.dnalabsinternational.com/email_newsletter/vol_50_aug_07/vol50_ref07.html
Indiana - It's been 22 years since Joel Lightfoot found the body of his younger sister Lisa, who was beaten, raped, stabbed and left on an embankment on Indianapolis' Near Southside.
A few weeks ago, Lightfoot got a call from Indianapolis metropolitan police detectives.
"It was definitely a shock," Lightfoot, 44, said Saturday.
"The detective called me back a few weeks later and said, 'We got him.' That's all I needed to hear."
Sgt. Mark Albert in a statement Saturday said Jimmy Atteberry, 48, was linked to the 1985 crime by biological evidence obtained in the initial investigation and entered into a national DNA database.
Atteberry has been serving sentences in a Missouri prison for rape convictions in Missouri and Illinois.
He most recently has been on pre-parole work release in St. Louis and now awaits transfer to Indiana to face the murder charge.
Lisa Lightfoot was 19 and in an early stage of pregnancy when she was reported missing on Sept. 21, 1985.
Her body was found the next day in the 900 block of South Pennsylvania Street, not far from where she was living with her boyfriend.
Source: http://www.dnalabsinternational.com/email_newsletter/vol_50_aug_07/vol50_ref08.html
Alabama - A man linked to the daytime rape of a woman in a Northwest Decatur alleyway turned himself in Thursday, police said.
The 37-year-old Decatur woman couldn't identify her attacker following the September 2006 assault, but DNA the man left behind allowed police to put a name to him, said Sgt. Terry White of the Decatur police Special Victims Unit.
Police arrested Craig Steven Bailey, 40, who gave them a Birmingham address, shortly after 11 a.m. Bailey went to the police department after learning a Morgan County grand jury had indicted him on a charge of first-degree rape, White said.
The victim "was taken to Decatur General Hospital, where she was treated and a rape kit was administered," White said. "The rape kit was taken to the Alabama Department of Forensic Science and they received a hit from CODIS."
According to the FBI, CODIS, the Combined DNA Index System, allows federal, state and local crime labs to exchange DNA profiles electronically.
Alabama takes DNA samples from all convicted felons, not just sex offenders.
Bailey, who is not a convicted sex offender, was in the system, White said.
"The Department of Forensic Sciences contacted us and told us they had received a match," White said. "It indicated Craig Steven Bailey's DNA was found in the kit."
A second DNA sample taken from Bailey confirmed the first match, White said.
White said examination of the woman also revealed injuries consistent with her story.
Although “at the time it occurred, the victim was unable to identify her attacker,” it later turned out he was an acquaintance, White said.
“It was not a stranger-rape type of situation. The guy with the hood, waiting for someone to come around the corner — that’s not this case,” he said.
Bailey remained in Morgan County Jail late Thursday in lieu of $20,000 bond.
Source: http://www.dnalabsinternational.com/email_newsletter/vol_50_aug_07/vol50_ref09.html
Michigan - A painter serving time in a state prison camp has been linked to the killings of three Flint women between 1998 and 2001, authorities said.
Ivan L. Page, 38, faces murder charges for allegedly strangling the women during a four-year span in Flint.
Officials said DNA evidence connected Page to the unsolved homicides that had stumped investigators for years:
Patricia Peeler, 34, whose nude body was found May 13, 1998, on E. Witherbee Street.
Lisa Marie Price, 31, whose body was found partially hidden on the lawn at 5610 Susan St. on Oct. 8, 1999.
Deena Brown, 34, who was found strangled with an article of clothing outside Northridge Academy on Jan. 20, 2001.
Police were to swear out a three-count warrant this morning charging Page with first-degree murder.
Although police had DNA evidence connecting the three deaths, Page's name didn't surface until last summer when police were alerted that there had been a hit in the state DNA database.
Page was sentenced to prison in March 2006 on a cocaine and weapons conviction in Flint and was ordered to give a DNA sample on his birthday.
When the sample made it into the state database, police said Page's name came up linked to DNA found at three crime scenes.
Source: http://www.dnalabsinternational.com/email_newsletter/vol_50_aug_07/vol50_ref10.html
Ohio - Authorities say new DNA evidence led to the arrest of an Ohio man whose testimony in a 1986 Texas murder case helped convict another man in the crime.
Fifty-5-year-old Gerald Pabst was once a suspect in the sexual assault and shooting death of Galua Crosby in Garland, Texas.
But prosecutors dropped a murder charge against Pabst, who passed a polygraph test and testified against Clay Chabot.
Chabot was then convicted of murder and sentenced to life in prison.
Ohio Attorney General Marc Dann's office says Pabst was arrested Monday at a bar in Geneva-on-the-Lake, about 50 miles east of Cleveland.
Dann says Pabst was extradited to Dallas County where he'll face perjury charges.
Dallas prosecutors are still determining if the DNA evidence exonerates Chabot.
Source: http://www.dnalabsinternational.com/email_newsletter/vol_50_aug_07/vol50_ref11.html
California - After nearly seven years, Merced police believe they have found the killer of 49-year-old Jacquelyn Faye Travis. He is a man convicted of killing two other people and suspected in a fourth murder.
Ronald James Ward, 41, is in custody at Montana State Prison in Deer Lodge, Mont. Detective Sgt. Scott Skinner of the Merced Police Department said they have solid DNA evidence linking Ward with Travis' Dec. 7, 2000, murder.
Merced County District Attorney Larry Morse II said Tuesday he and Stanislaus County District Attorney Birgit Fladager want to coordinate efforts in prosecuting Ward, also suspected in the Dec. 30, 2000. killing of Shela Polly in Modesto.
Morse and Fladager hope to visit with Ward, serving a life term in the Montana prison, to see what his intentions are. Morse said they are trying to avoid two separate and costly trials.
"He will have to stand trial in Merced County or make a plea. If the only way to bring justice is to extradite him, we will. We want to hold him (Ward) fully accountable for crimes in Merced and Modesto," Morse said.
Skinner said police detectives have presented their case to the District Attorney's office and are awaiting a formal decision.
Ward, a former truck driver, homebuilder and commercial fisherman, is serving a life sentence for the October 2000 murder of Craig Sheldon Petrich, 43, of Corvallis, and the August, 2000 murder of Kristin Laurite, 25, in Arkansas.
The body of Polly, the divorced mother of three youngsters, was found Dec. 30, 2000 near Dry Creek in Modesto by a man walking his dog. She had been beaten, stabbed and sexually assaulted.
In June of 2007, Ward was given a life sentence in Arkansas when DNA taken from semen linked him to the murder.
In an interview with the Missoula, Mont. Missoulian, Ward denies any memory of the murders in Arkansas or California but doesn't deny he was responsible.
Source: http://www.dnalabsinternational.com/email_newsletter/vol_50_aug_07/vol50_ref12.html
Massachusetts - Suffolk District Attorney Daniel Conley said police might not have caught the ex-con accused of raping his wife’s 67-year-old neighbor had legislation not been passed in 2004 to retroactively record the DNA of all convicted felons.
The DNA of Raymond Epps Jr., 50, was not in the state database when he began serving a seven-year sentence in 2001 for breaking and entering. But it was there when he walked out of MCI-Cedar Junction on June 23 - one month and a day before he allegedly brutalized and threatened to kill the South End victim.
Because the Massachusetts District Attorneys Association pushed to expand the DNA database beyond violent felons, “We were able to identify a suspect very rapidly and make an arrest far sooner than we would have prior to 2004,” Conley said. “In fact, Epps probably would have gone free.”
Epps, whose criminal history dates back to 1974 and whose aliases include Monty Garrett, was held on $750,000 cash bail by Judge Sally A. Kelly after pleading not guilty yesterday in Boston Municipal Court to aggravated rape, kidnapping and unarmed robbery.
In addition to his DNA being a match in a rape-kit test, police have recovered from Epps’ wife’s home in the same apartment building clothing matching a description provided by the victim, as well as a towel she said he stole from her apartment on July 24and a pair of pearl earrings, her mother’s birthstone ring and a diamond ring.
“Mr. Epps denies it - denied it to the police who arrested him,” said defense attorney Christopher Skinner.
Source: http://www.dnalabsinternational.com/email_newsletter/vol_50_aug_07/vol50_ref13.html
For additional health information, visit OhioHealth
Did You Know?
Topic: Making an impression
Bite-mark study could bolster use as evidence
By BRANDY BENEDICT
It's commonly believed that no two sets of human teeth are alike. Chips, jagged edges, crooked teeth and gaps all contribute to a person's unique smile.
It seems reasonable, then, that bite patterns made by those teeth should be as unique as the teeth themselves, though this has not been scientifically proven.
Now, a team of researchers at Marquette University has gotten one step closer.
By measuring the position and rotation of individual teeth from hundreds of bite samples collected from volunteers, the researchers can statistically estimate how often the characteristics of a particular bite pattern occur in the population and determine the probability of someone else having the same characteristics.
The researchers ultimately hope that the scientific analysis of the patterns will provide a more objective basis for analysis and comparison of bite-mark evidence in criminal trials.
"This project will put science behind the impression that a person's pattern of bites is unique," said Thomas Radmer, assistant professor and director of oral and maxillofacial surgery at Marquette.
L. Thomas Johnson, adjunct professor at Marquette University's School of Dentistry, explained that while intuition may say that each set of teeth would make a distinct bite pattern, there is no scientific database proving it.
So Johnson and Radmer decided to create one.
During a two-year period they collected more than 400 bite patterns from male volunteers ages 18 to 44, the demographic most likely to be the aggressors in violent crimes involving biting.
Each subject bit down on a copper-coated wax wafer, simultaneously capturing the indentations of his top and bottom teeth. The copper coating on the wafer ensured that the bite marks would show up clearly when scanned into a computer.
For each sample they measured six characteristics: tooth width; degree of rotation of a tooth; inward or outward displacement; arch width; spaces between teeth; and any missing or extra teeth.
Measurements of each bite mark pattern initially were taken by hand and had to be checked for consistency.
"This is not an exact science; it's a bit subjective," Johnson said. "There has to be a human mind and eye to compare."
Now, a computer can do all the hard work and get it right every time.
Thomas Wirtz, director of the dental informatics program at Marquette, developed a computer program to measure the bite pattern characteristics automatically, eliminating any errors in measurement.
His program looks at every pixel in the image to locate the positions of all the teeth, and then uses formulas to calculate distances and angles.
It takes 15 to 20 minutes to measure a sample by hand, but Wirtz's computer program can do it in about 10 seconds, a huge improvement considering the researchers ultimately would like to build a database of tens of thousands of samples.
"Without the automated program it would be a monumental task," Radmer said.
Controversial as evidence
Bite marks have a controversial history as evidence in criminal trials. First brought up as forensic evidence in 1870, bite marks did not formally gain legal credibility in the U.S. courts until 1954. Since then, bite-mark evidence has been used in a number of cases, most famously to convict serial killer Ted Bundy.
But occasionally forensic dentists have been known to make some costly mistakes.
In April 2002, DNA evidence freed Ray Krone, dubbed the "snaggletooth killer," who spent 10 years in an Arizona prison, including two on death row, based solely on incorrectly analyzed bite marks.
Bite-mark patterns can vary wildly in clarity, and like a bruise, they can change over time. The quality of a bite mark also depends on the substance a person has bitten, as bite marks on gum or Styrofoam cups can be more defined than bite marks on skin. The force of the bite, the angle of the bite and the area bitten can all affect the appearance of a bite mark.
Forensic dentists apply their expertise to formulate an opinion on whether the accused could have made the particular bite mark patterns.
But the subjective nature of bite-mark analysis and interpretation has been the focus of harsh criticism, and forensic dentistry has been called a "junk science."
"False convictions leave bite marks with a black eye," said Donald Simley, a certified forensic dentist based in Madison. The study "should help the whole science of bite-mark evidence."
Radmer agreed: "The defense attorneys have been taking aim at this type of evidence in jury trials as being subjective, not objective."
'Worthwhile' study
With statistics to back up professional opinion, the researchers hope to make bite-mark forensics more scientifically sound.
"What the Marquette study is trying to do is provide an objective, reliable basis to answer the critics," said Daniel Blinka, a professor in the Marquette Law School and legal consultant for the study. "It has a broader significance in providing a template for other areas of forensic expertise, like fingerprint and handwriting analysis, to look to and follow."
Wirtz's computer program could be adapted to measure the width of tire treads, or width of ridges in a fingerprint. "There are multiple applications throughout the field of forensics," Radmer said.
The study was funded with a nearly $110,000 grant from the National Institute of Justice through the Midwest Forensic Resource Center, part of the Ames Laboratory Research Center at Iowa State University. The researchers expect to complete their study by Sept. 30 and will present results in February at the annual meeting of the American Academy of Forensic Science in Washington, D.C.
The researchers agreed that the pilot study shows there is some predictability and provides a basis for further studies.
"We've shown with a very high confidence level that the (bite) pattern is unique," Radmer said.
Johnson, too, is pleased with the results: "I think it was worthwhile."
Source: http://www.dnalabsinternational.com/email_newsletter/vol_50_aug_07/vol50_ref14.html
Events and conferences for 2007 that may of interest to you include:
18th International Symposium on Human Identification - October 1-4, 2007
Renaissance Hollywood Hotel - Hollywood, California
Web site: www.promega.com/geneticsymp18/
The DNA Informant is a free bi-weekly email newsletter, published by DNA Labs International.
DNA Labs International is a private, ISO 17025 Accredited, Forensic Serology and DNA Identity Testing Laboratory, founded in 2004 by a Board Certified Fellow in Molecular Biology with over two decades of experience in Forensic Serology and DNA Analysis in United States Crime Labs. Our primary mission is to help our clients identify criminals within their jurisdiction by providing timely, accurate and cost effective DNA testing results. To do this we created an organization based on industry best practices from over 20 State Crime Labs around the United States. We are located in Deerfield Beach, Florida, just minutes from the Fort Lauderdale airport.
DNA Labs International’s services are now available for individual cases and outsourcing contracts. Please keep us in mind as you start to consider your outsourcing needs, regular and rush cases and DNA case review.
Editor: Karen Daurie
Karen.Daurie@DNALabsInternational.com
If you would like to be removed from our mailing list, please click on http://www.dnalabsinternational.com/remove_newsletter.html
