SciBlogs

Archive February 2010

Hair, science and crims Anna Sandiford Feb 28

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Analysing hair for criminal casework purposes has had some new developments recently, as reported in Forensic Science International. For your delectation and delight, and as the journal has a log in, I have decided to share some of the papers that deal with day-to-day issues to which we can all relate: In Sweden, if someone is convicted of either drug crimes (described as “petty”, presumably referring to possession only) or drug driving, their driving licence can be revoked. In order to regain their licence the driver must prove that they have been drug-free for a given period time. As anyone working with drug offenders knows, it is relatively easy to pass a drug urine screening test: either abstain for a relatively short period or cheat the results by using someone else’e urine (there’s a black market for ‘clean’ urine – think Gattaca). When drugs are consumed, the pattern of use is recorded in hair, particularly in head hair. A Swedish study has looked at the viability of using hair analysis instead of urine analysis when assessing whether or not to return someone’s driving licence to them. Interpretation has several issues (including understanding and knowledge of the screening method limitations) but the people being tested apparently approved of hair sampling “considering it a better means to prove their drug abstinence. In addition, both the clients and the clinicians thought hair sampling easier than urine sampling.” (Hair analysis for drugs in driver’s license regranting. A Swedish pilot study, Pages 55-58, Robert Kronstrand, Ingrid Nyström, Malin Forsman, Kerstin Käll). As with all cases where people have to prove drug abstinence by providing a sample of hair for analysis, it’s always interesting when they turn up to have their sample taken but have just come from the hairdressers where they had a Number 1….. In Italy, a study has been completed to “investigate acute and chronic exposure to environmental tobacco smoke (ETS) in a cohort of young adolescents using urinary cotinine and hair nicotine testing after recent implementation of Italian smoke free legislation,” which has implications for everyone. The overall conclusions were that “due to the implementation of smoke-free legislation and information campaign against smoking, a significant trend toward low exposure to ETS was observed in this study cohort with no association between exposure to ETS and respiratory illnesses.” What I did find interesting was this: “Hair nicotine was inversely related to educational level of the adolescents’ parents” – not just the comment itself but the way it was phrased. It must have taken a while to phrase that appropriately… (Assessment of exposure to environmental tobacco smoke in young adolescents following implementation of smoke-free policy in Italy, Pages 97-100, M. Pellegrini, M.C. Rotolo, S. La Grutta, F. Cibella, O. Garcia-Algar, A. Bacosi, G. Cuttitta, R. Pacifici, S. Pichini) Finally, a French study investigated something that I find to be utterly fascinating: “Heroin markers in hair of a narcotic police officer: Active or passive exposure?” I think the Abstract just says it all without any need of assistance from me: In “March 2007, a police officer (46-year-old man) and a clerk (37-year-old woman) were arrested and subjected to investigation on the charges of drugs of abuse trafficking. The loving couple was exploiting their administrative positions to make money with the resale of seized drugs. The laboratory was requested to analyse their hair for drugs of abuse. Hair of the 2 subjects tested positive for heroin by GC–MS. A few days later, analysis of hair obtained from 11 other police officers of the same unit was requested, in order to compare the results, as external contamination was proposed to account for the positive results. The aim of the investigations was to demonstrate that passive contamination could not occur for persons dealing every day with drugs of abuse with minimal caution and hygiene, and that the measured concentrations in the arrested subjects correspond to personal abuse. All the narcotic team tested negative, irrespective of the compound.” And that’s this month’s round-up of Forensic Science International….

Burglary science Anna Sandiford Feb 23

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Burglars are apparently more likely to wear Reebok Classic trainers than other brands of training shoe. This is one of the findings of a recent scientific study of the running shoes of choice used by burglars in the English county of Northamptonshire. These results tie in nicely with my own (professional) experiences of burglary cases in England & Wales and also confirm my comments on misc.ience’s post If I was a running shoe manufacturer, I would be worried… The study also found that burglars from poorer areas tended to wear more expensive trainers, which follows many people’s observational experiences, and the average cost of trainers worn by unemployed burglars was greater that those worn by burglars with jobs. Understandably perhaps, the study had no knowledge of whether or not said trainers were bought or stolen…..

DNA, Peter Gill and the CSI Effect Anna Sandiford Feb 17

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I’ve been preaching for some time now about the problems that programs like CSI cause regarding the general perception of the capabilities of forensic science – and look, here is one of the world’s foremost DNA scientists and pioneers of DNA in forensics saying exactly the same thing, specifically about DNA: CSI no relevance to real DNA profiling. Dr Gill also mentioned that although TV programs have highlighted science (which is a good thing), they do hinder the Expert when it comes to presenting evidence in court. I wholeheartedly agree. Dr Gill said, “(CSI) doesn’t really represent the way in which forensic science works. My concerns with programs like that it gives the impression that if there is a DNA profile found at a crime scene and you have a suspect that it doesn’t necessarily follow that a suspect is guilty of that crime. There are a lot of other things which must be considered.” – this is so true.  Forensic Scientists shouldn’t necessarily just report (or review) the science in isolation – the framework into which that science fits is crucial for the proper understanding of what the science is telling the Trier of Fact (usually a jury and/or a Judge). It is then for the Trier of Fact to decide what weight to apply to that evidence when deciding on the Ultimate Issue, which is usually down to two choices: guilty or not guilty. Forensic Science can of course also be used for investigative purposes – and it may take an investigation down a different track from the one that the investigators were expecting. The important thing is that the investigators should take that scientific information into account when deciding what to do next – just sticking with their previous track of thought may be neither appropriate nor correct. “The scientist is not there to prosecute anyone. Whether the individual is found guilty or innocent has no bearing on the science.” Dr Gill makes an extremely valid point in this last sentence.  ALL forensic scientists should be impartial and unbiased in their reporting – no exceptions.

Forensic science: validation and incompetence Anna Sandiford Feb 12

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U.S. academics at UCLA are being granted funds to consider error rates in latent fingerprint evidence.  Some would ask whether or not this sort of exercise should have been completed loooong ago.  As with any other area of applied science, regular review should be undertaken.  Unfortunately, this is not something that necessarily occurs in forensic science, partly because some agencies aren’t keen on their databases being examined (see Crime DNA databases should be independently examined). Last year, the United States National Academy of Sciences issued a damning report on the state of forensic science in U.S. crime laboratories.  The report basically stated that the accuracy and reliability of practically all forensic science methods, ranging from glass to fingerprints, had not been established adequately through rigorous scientific scrutiny.  At the end of this month (Feb 2010), the American Academy of Forensic Sciences (AAFS) is holding its annual scientific meeting, which is tellingly entitled, Putting Our Forensic House in Order: Determining Validation and Expelling Incompetence.” So, not only is forensic science in the States being shaken upside down until the grotty bits drop out of its pockets, someone somewhere is getting paid to do the work that should have been done long ago, on an ongoing basis. Let’s hope one of the resolutions that arises from the AAFS meeting is that forensic science techniques should be reviewed regularly. The problem is of course that most people working for the prosecution don’t really want any technique investigated too deeply in case problems are found. Once that happens then other convictions might be called into question, which could throw the whole system into disorder, incurring enormous expense and all the obvious associated problems. To my mind, that’s not a good enough reason not to do it.  If people are going to be sent to prison based, even in part, on scientific findings then the science must be robust and reliable (as well as other legal issues such as relevant and repeatable).  If science is reviewed regularly and the law takes that into account then it should be possible to work out a system whereby the courts can be sure that the science is up-to-date, which in turn adds to the strength of science in court.  It also might present the current stink that’s going on in Texas over the inadequate forensic science presented in the case of Cameron Todd Willingham (Wikipedia link), who was executed for allegedly killing his children in a house fire he was supposed to have set.  The science has since been shown to have been wrong. The other thing to remember is that if the overall outcome of the US review and the work being carried out to address those issues identifies some real problems, the implications could be felt throughout court systems worldwide – including New Zealand.

www.FSRL.co.nz/blog – new blog location Anna Sandiford Feb 11

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This blog has moved to http://www.fsrl.co.nz/blog/ because it’s now integrated into our company webpage.

Veneer to the rescue! Anna Sandiford Feb 11

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There’s a man in China who’s very glad about varnish and veneer. Despite his fingerprints being found at the scene of a theft, he was discharged by the judge who was presiding over his trial for said theft (Driver nearly convicted for incidental fingerprints). The reason was because the fingerprints were beneath a veneer on a deity altar and had been deposited by the freed man more than ten years previously, at a time when he had been working for a company that made such deity altars. The altar was then bought by the victim of the theft, who took it home and from where it was later stolen. The Court also believed the discharged man’s alibi – he was working as a truck driver at the time of the crime. The presiding judge thought it unlikely that he would have abandoned his truck on the side of the road to commit a random theft. Case circumstances are so varied – no two are ever the same….

DNA evidence causes case to be dropped SciBlogs Feb 10

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Peter Williams QC topped off a successful legal career last week by successfully applying for the case of Zion King to be discontinued.  The Crown supported Mr Williams’ application and the Judge granted it.

Zion King was charged with the murder of Chattrice Maihi-Carroll in March 2008  after the deceased was found with stab wounds on 21 January the same year.

Key points that resulted in the dismissal of the case were problems with the statements of Crown witnesses about when Mr King had told them he knew about the death – it seems the first statements indicated he had known about it before news had been released to the general public, which meant that he must have been involved with it.  Further investigations showed that he had actually not known about it before everyone else.

Also crucial to the dismissal of the charges was the DNA evidence – or lack of it.  Mr Williams pointed out evidential matters that supported his application for the case to be discontinued, as follows:

a) Reasonable possibility DNA excludes accused;

b) No forensic evidence against accused;

c) Accused had no relationship with deceased;

d)  [not related to DNA];

e) Deceased suitor’s blood on pillow;

f) Unidentified male DNA on glass on kitchen bench;

Considerable effort was put in by the Defence team to investigate matters so that the above points (as well as others) could be supported.  To quote Hawke’s Bay Today (because it’s not clear from the article who said it), “The case had [sic] revealed “how essential it is for defence to investigate independently”.  I couldn’t agree more.

Cocaine on money, drug traces on banknotes Anna Sandiford Feb 10

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I was surprised at a news article in the English MailOnline, which states that Every British bank note is contaminated by cocaine within weeks of entering circulation. I wasn’t surprised about the cocaine issue, but about the fact that the media seemed to think this was new or unusual. I’ve been working on cases involving drug traces on banknotes since 2002 and even back then 95% of English banknotes were contaminated with traces of cocaine. To my mind, the most comprehensive database dealing with drug traces on banknotes is compiled and maintained by a company in the West Country of England. When I left England in 2008, practically 100% of banknotes in the database were contaminated with cocaine (and not just contaminated but high levels of contamination), less were contaminated with MDMA (from Ecstasy) and amphetamine, and less still with diamorphine (from heroin) and THC (from cannabis).  The company is question is not one of the mainstream prosecution laboratories but a standalone organisation that has developed specific equipment to deal with analysing traces of drugs on all sorts of items including vehicles, clothing, mobile phones and, of course, banknotes. It should be remembered however that the traces of drugs we’re talking about here are so minute that they can’t be seen with the naked eye.  To put it into perspective, if one took a grain of salt and divided it into 1,000 pieces and then if one took one of those pieces and divided again into 1,000 pieces, this is the level of contamination that the anaytical equipment can detect – it’s teeny, teeny tiny.  The other way to look at is if the total amount of drugs present on one million English banknotes (each contaminated with this small weight) was bulked together it would amount in size to no more than a single grain of salt. Drug traces on banknotes can be extremely valuable for assisting Police and Customs to determine whether or not seized quantities of money have been involved with the drug trade but cocaine has always been a difficult one to interpret.  Wouldn’t it be great if the technology could be applied in New Zealand, given that there is such a problem with P here?

Wildlife forensics & the UN: fighting illegal fishing Anna Sandiford Feb 02

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The United Nations (UN) is looking to adopt a forensic science approach to assist in managing the problem of illegal fishing. At a UN Food and Agriculture Organization workshop in Rome they discussed what techniques could assist and how: UN turns to forensic science to help combat illegal fishing. “DNA analysis can unveil the species of a suspect white fillet, for example, and chemical tests on fish ear bones reveal absorbed nutrients to pinpoint the region where they were caught, major weapons in combating unscrupulous fishers and traders who game the system to prevent over-fishing and avoid international restrictions aimed as preserving fish stocks, as well as taxes and other limits.”

I always say that there is no end to the types of casework to which a forensic science approach can be applied and this is a perfect example of this in action. Particularly given that one participant at the UN meeting described how “a group convicted of illegally trading abalone confessed that they learned techniques for destroying evidence by watching CSI: Miami. It’s that CSI effect again, only this time it’s gone really bad.

Police resources; Mt Eden taxi driver murder Anna Sandiford Feb 02

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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.