Police resources; Mt Eden taxi driver murder

A Police Alert today said, “There are now forty investigators and police officers involved in this homicide enquiry. Every available resource at our disposal is being used.” This is to try to catch the killer of an Auckland taxi driver who was stabbed to death whilst he was working last weekend.
A UK police force recently solved a murder by applying a massive amount of man power (and resources) and a man was successfully prosecuted, even though a body was not found for months after the start of the investigation: Old-fashioned police work solves case of GP killed by jealous man.
In the absence of a body, all the Police had to work on was a potentially powerful motive (jealousy) and a lack of any activity involving the missing man. Police contacted every hospital, dental surgery, supplier of gas, water, electricity, satellite, cable TV, bank and mobile phone provider in the COUNTRY to see if the missing man had made an appearance somewhere else, as well as ports and airports – but nothing. That is an enormous amount of effort, man power and time.
Police suspected that the missing man’s car had been used to transport his body so they checked petrol records to see how much fuel would have been in the car’s tank on the night he went missing so they could establish how far it could have been driven. The missing man’s car was also examined for soil and pollen to suggest where it may have been.
The Police had a suspect and so they examined CCTV footage to track the movements of the missing man’s car as well as that of the suspect (there’s a good argument right there for automatic numberplate recognition cameras and data recording). They pieced together the suspect’s movements on the relevant night and determined that he had had four hours to dispose of the body. So then they worked out how far he could have travelled in that time.  The search took them over an enormous area.
Police divers searched water bodies.
Dogs detected a scent in some woods where Police then found a wheelbarrow among the trees. Officers then spent hours sifting through photographs and videos at the suspect’s house, looking for a photograph of the wheelbarrow – and they found one. Five months after he disappeared, the missing man’s body was located in a very deep grave, dug by a man who knew how to dig holes – the suspect had been a telecomms engineer and dug holes for a living.  Overall, the Police put an enormous amount of effort into this case – it’s a gift to Hollywood just waiting to be made.
It maybe would also give hope or comfort to the family of the Auckland taxi driver that the Police resources will be enough to find the person or people who did it.

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Bitemark evidence – another example of the need for a database

The following article appeared in Science Daily on 17 September 2009.  It seems that this field of expertise, bitemarks, has fallen foul of the usual criticisms of unusual evidence types – the lack of an adequate, representative database for interpretation of information in a given case.  Without such a database there is no real way to objectively and statistically interpret scientific findings.   Attempting to present such scientific findings as evidence in court often fails because the science does not meet the basic criteria for evidence to be presented in court; depending on the jurisdiction that may be the Daubert or Frye rules or just whether the evidence is reliable, relevant and repeatable. This criticism has been levelled at several areas of forensic science notably, in my career anyway, drug traces on banknotes.

I also remember there was a famous case in the UK where an IRA bomber ate an apple at a “location of interest”, discarded the core and the core was recovered by the Police.  His dental alignment was compared with the apple core and he was positively identified as being the apple eater.  From distant memory, this linked the apple-eater into a significant terrorist event.  This was in the days before DNA. In today’s courtroom, it’s unlikely that the apple bite would be accepted as evidence in isolation; corroborating evidence would be required because, on its own’ it’s circumstantial and potentially more prejudicial than probative.

On a lighter  but practical note, I’m glad they used stone teeth in the following study, rather than live people to bite the cadavers….

“Bitemark evidence and analysis should be approached with caution, according to study

Against the backdrop of last week’s [US] Congressional hearing into the future of forensic science, researchers from the University at Buffalo’s Laboratory for Forensic Odontology Research in the School of Dental Medicine, have published a landmark paper on the controversial topic of bitemark analysis.  The Congressional hearing focused on the findings of a National Academy of Sciences (NAS) report on the scientific basis of forensic disciplines. Among the pattern evidence fields (fingerprints, tool marks, etc.) that were reviewed in the NAS report, bitemark analysis received critical commentary. During the hearing, Innocence Project co-founder Peter Neufeld introduced Roy Brown, wrongfully convicted on bitemark evidence and later exonerated through DNA analysis.

In anticipation of the NAS report, the new UB study published in the Journal of Forensic Sciences challenges the commonly held belief that every bitemark can be perpetrator identified.  “Bitemark identification is not as reliable as DNA identification,” explains the study’s lead author Raymond G. Miller, D.D.S., UB clinical associate professor of oral diagnostic sciences.  “With DNA, the probability of an individual not matching another can be calculated,” he says. “In bitemark analysis, there have been few studies that looked at how many people’s teeth could have made the bite.”

Miller’s co-authors include UB’s Peter J. Bush; Robert Dorion, D.D.S., DABFO, UB adjunct professor of oral diagnostic sciences; and Mary A. Bush, D.D.S., UB assistant professor of restorative dentistry. Dorion is the editor of the only comprehensive textbook on the subject of bitemarks in forensic science, Bitemark Evidence: A Color Atlas and Text, and is currently the odontology section representative to the board of directors of the American Academy of Forensic Sciences.

The current study investigated three main questions: is it possible to determine biter identity among people with similarly aligned teeth; is it possible to determine how many individuals from a larger sample might also be considered as the biter; and, if there is bite pattern distortion, is it enough to rule out a specific biter while still including a non-biter?

To answer these questions, the researchers gathered 100 stone dental models (replicas of the dentition), which were measured and divided into 10 groups based upon the misalignment patterns of the teeth. After randomly selecting one model from each of the 10 groups, the researchers impressed bitemarks on cadaver skin. After the bitemarks were created, they were then photographed and the indentations were compared to the dentitions using overlays created with photographic software.

The authors are one of the first to use a human skin model rather than animal models or non-elastic biting substrate, such as wax or Styrofoam. Current human subject restrictions limit experimentation on living subjects.  “Living bitten tissue may bleed or bruise,” explains Miller. “The initial bitemark indentations rebound shortly after infliction often leaving a diffuse bruising that may be difficult to measure accurately. The indentations produced in our study represented the best conditions for measurement.”

The results indicated that when dental alignments were similar, it was difficult to distinguish which set of teeth made the bites. Distortion noted in the bitemarks allowed matches even from different alignment groups. Therefore, the researchers concluded that bitemarks should be very carefully evaluated in criminal investigations where perpetrator identity is the focus of a case.

As Miller notes, “In the past 10 years, the number of court cases involving bitemark evidence that have been overturned led us to question the reasons for the erroneous bitemark identification. It’s important to recognize the serious consequences of a misidentification for the accused, the victim, the families involved, the justice system and the possibility that the perpetrator is still at large.”

US execution: not arson

This is a news item that has popped up many times over the past few days.  If the reporting is accurate then it is a classic example of how things can go wrong in a scientific investigation.

Faulty fire investigation led to execution

Associated Press

A fire investigation that led to the execution of a man in the deaths of his three young children was so seriously flawed that its conclusion of arson can’t be supported, a fire expert hired by the state said in a new report.

In a report to the Texas Forensic Science Commission released Tuesday, Craig Beyler said the fire investigation in Cameron Todd Willingham’s case didn’t adhere to the standards of care in place at the time, nor to current standards.  Beyler, chairman of the London-based International Association for Fire Safety Science, said in the report that the opinions of a state fire official in the case were “nothing more than a collection of personal beliefs that have nothing to do with science-based fire investigation.”

The commission, created in 2005 to review forensic misconduct allegations, requested the independent analysis after the Innocence Project submitted claims of questionable evidence in the cases of Willingham and another man who was convicted in a similar case but was later released.  Commission Chairman Sam Bassett called Beyler’s report “a major step” in the panel’s review of both cases.  Before issuing its final report, the commission will seek responses from the State Fire Marshal’s Office and other parties, and will interview Beyler in October, Bassett said.  He said he expects the commission to release its report next spring.

Beyler said that in both cases, “The investigators had poor understandings of fire science … Their methodologies did not comport with the scientific method or the process of elimination.”  He said Manuel Vasquez, a deputy state fire marshal in the Willingham case, appeared “wholly without any realistic understanding of fires and how fire injuries are created.”  Beyler said witnesses contradicted Vasquez’s arson hypothesis and that Vasquez admitted he had not eliminated other possible causes.

Eric Ferrero, spokesman for the Innocence Project, said Beyler’s findings on the Willingham case “confirms what several experts have found over the last five years after reviewing thousands of pages of evidence.”  “Every expert who has looked at this case has determined there was no reason to call it arson,” he said.

Willingham, 36, was executed in 2004. He was convicted of setting the fire that killed 2-year-old Amber and 1-year-old twins Karmon and Kameron on Dec. 23, 1991, in their Corsicana home.  He told The Associated Press before his execution that he was innocent. “The most distressing thing is the state of Texas will kill an innocent man and doesn’t care they’re making a mistake,” he said.  Willingham’s cousin said she has never doubted her cousin’s innocence. Family members tried for years to free him.  “I would definitely like the state of Texas to take responsibility and admit in fact they wrongfully executed Todd Willingham,” she said. “Is that going to happen? Probably not. I’m not optimistic.”  Willingham’s stepmother, Eugenia Willingham, called the report another step in the “long, drawn-out process” of clearing his name.  “He lived 12 years on death row,” she said. “He went through hell, I’m telling you. It was probably worse than hell.”  She said her husband died in 2005, the year after his son’s execution, of prostate cancer and “a broken heart.”

Vasquez investigated the case with Douglas Fogg, the assistant Corsicana fire chief. The report said they cited burn patterns on the floor of the children’s room, hallway and porch, indicating an accelerant spill. Beyler said those determinations have no basis in modern fire science.

Ben Gonzalez, a spokesman for the Texas Department of Insurance, of which the State Fire Marshal’s Office is a part, said he had no comment on the report, saying officials there had not yet seen it. He said Vasquez died in 1994.

In the other case cited in the report, Ernest Ray Willis was convicted in 1987 in a fatal house fire in Iraan, but was freed after 17 years on death row when a federal judge ruled that authorities concealed evidence and needlessly drugged him during his trial.”

Another comment on court attendance….

Having thought about my earlier post regarding court attendance, I now remember an interesting exchange with a senior judge at a conference once, which might explain why Legal Services is looking in the wrong place for savings in the UK court system.  The exchange went something like this:

Judge:  There is a real need to make savings at court for money spent on experts.  That is why the hourly rates are capped.  Experts spend far too much time wasting the court’s time and money by stringing out the amount of time they are at court.

Scientist: I  don’t think that’s a very fair comment.  An easy way to save money would be to make sure experts don’t attend court unless they have to.  I regularly attend court only to be told that my report was agreed the week before.  The court gets a full day’s bill because I’ve travelled across the country to get there just because no-one bothered to tell me I wasn’t needed.

Judge:  I don’t believe that ever happens.  When was the last time that happened?

Scientist:  Yesterday.

Judge:  I don’t believe that would happen.  If that sort of thing happens then you should go into to court to advise the judge or Magistrates of what has happened so that they can make sure it doesn’t happen again.  I don’t believe that ever happens [bluster bluster bluster – end of conversation].

Who has ever been to court and then been allowed to go into the court to tell the judge or Magistrates that they were called there unnecessarily?!  It’s just not going to happen.  This to me is a prime example of the judges believing that they know what goes on behind the scenes when in fact they know only what Counsel chooses to tell them.

David Bain retrial, 2009

I get asked about this case all the time.  It was probably New Zealand’s biggest ever case in terms of media attention (more like frenzy) and overall cost.  It is also probably New Zealand’s most controversial case and people have an opinion before they even ask me about it.  It’s a bit like when a woman announces she’s pregnant – people react according to how they feel about pregnancy and children, not how they feel about that particular woman being pregnant.  When people ask  me about the case it’s generally because they have an opinion about it and they want to voice it.

I was approached by Joe Karam in October 2008 to ask if I could assist with the forensic science issues in the David Bain retrial.  I had never heard of David Bain or Joe Karam and it was just another case to me.  As a forensic scientist, all cases should be treated the same, regardless of their perceived importance.

For various reasons, my company was involved with several areas of the forensic science and also with Witness Liaison for the duration of the trial.

It was an extremely interesting case for many reasons.

That’s all I have to say.

Drug traces on banknotes: Scotland

During my time in England I had the pleasure of being involved with many cases involving drug traces on banknotes.  For those of you in countries with plastic money (such as NZ or Australia), those who live in countries with paper money have the joy of carrying around with them banknotes of which practically all will bear minute traces of cocaine.  At the last look, 70% had traces of MDMA (Ecstasy), 5% had traces of diamorphine (heroin) and 5% had traces of THC (found in cannabis).  Banknotes are seized in a variety of cases including criminal cases, Customs & Excise and under the Proceeds of Crime Act.  Some nice people at the lab will analysis a selection of banknotes (in a non-destructive manner – not that that matters if the Defendant is found guilty because they won’t be seeing their cash again).  Sometimes, those nice people at the lab will travel to court to give evidence about what they found.  Sometimes, someone like me might go along as well to add comment for the Defence.

Anyway, this story is another about court attendance, this time where I was involved as a Defence expert for a case in Scotland.  I only went because my boss was on holiday somewhere exotic (again) and he couldn’t make it, so I had to go.  After getting stuck on the M1 on the way to Luton airport (pouring rain, stationary traffic for an hour) I missed my flight to Aberdeen.  Had to get on the next flight, which was to Edinburgh.  Happily, the barrister was in Edinburgh so he picked me up at the airport and we drove to Aberdeen.  I have no idea how long it took except it seemed a loooong time in a car with someone I had never met before.  In fact, I had never even spoken to him before.  This is the sort of thing that your mother warns you not to do.

I spent five days in Scotland.  It snowed and there was no heating  in the hotel.  I had no thermals with me.  There was porridge for breakfast though, which was good (no other meals necessary for the rest of the day).  The Crown’s scientists came and went.  I stayed (just in case I was needed, but I wasn’t).  The Crown wanted to show the tape of the Police interview but no-one knew how to work the video player.  Rather than allow us to try to work it out for ourselves, court was adjourned for half a DAY so that a technician could drive from Aberdeen to “fix” it (only a Certified Technician was allowed to touch it – against Health & Safety rules otherwise).  Technician arrives, presses a switch, VCR starts to work, we all get back to the trial wondering why a) Health & Safety rules had got so mad, and b) why the Technician couldn’t have told us over the phone which button to press.

There were many other things about that case that were bizarre (the defendant was found guilty; defendant went to prison; case was appealed; defendant was released).  Another bizarre incident involved a mobile phone (no, not one that had been swabbed for the presence of drug traces).  A mobile phone rang (very quietly, I might add).  The Judge stopped the proceedings and demanded that the offender place at least a pound, but preferably a banknote of some denomination, into the charity jar he kept on the Bench.  I leaned over to the solicitor and commented that this was indeed a strange occurrence.  He leaned back and said “Well, it’s just as well we’re not in the court room next door – the judge in there puts people in the cells for an hour if a phone goes off in his court, even if you’re a QC.”  I believe him.

Fabrication of DNA evience: revisited

I have been keeping an eye on media reports about the issue of fabrication of DNA evidence and everyone seems to be very excited about it, particularly how it will bring forensic science crashing to the ground and CSI ratings will plummet.

However, if one thinks about it, fabrication of any evidence type is not particularly difficult.  In a lot of cases there is generally more to it than just one science type.  I appreciate that DNA seems to be the trump card but those of us working in the industry know its limitations and comment accordingly.  If there is a conflict between the scientific data then more attention to detail is required and the findings should be reviewed.  If only DNA is being used (say, in a Cold Case Review) my experience so far has been that Police and prosecutors are aware that they shouldn’t put all their eggs in one basket and make sure that they have more to their case than just a DNA hit on a database.

Rather than sinking CSI‘s ratings, I’m sure the writers can now use this as a new storyline and the baddies will still be caught and it will all be sorted out in an hour and no-one will have smudged their lipstick, not even Laurence Fishburne…