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Posts Tagged Forensic Casework experiences

Drugs, driving and saliva Anna Sandiford Aug 02

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After a brief airing on RadioLive this morning to talk about a recent press release regarding drug/drink driving statistics, I thought it pertinent to add a little something to clarify what I was saying (three minutes is not a long time to say what you need to say on an issue as big as this!).
Firstly, the press release relates to a report prepared by ESR using data gathered over a five year period. The data concerned 1046 drivers who died between 2004 and 2009 (89 per cent of dead drivers during that time). These individuals were tested for alcohol and drugs and nearly half (48 per cent or 500 drivers) tested positive. “Of those, 72 per cent or 365 drivers had either used cannabis, alcohol and cannabis, or a combination of drugs”, AA’s general manager for motoring affairs Mike Noon said.
The report showed that:
* 135 (27 per cent) had used alcohol alone;
* 96 (19 per cent) had used cannabis alone;
* 142 (28 per cent) had used both alcohol and cannabis; and
* 127 (25 per cent) had used a combination of drugs, which may have included alcohol and/or cannabis.

I haven’t seen the report but I would be interested to know what “tested positive” means. At what level is an individual deemed to have been “positive” for alcohol, i.e. did it include any level of alcohol or only levels in excess of the legal limit? Similarly with the drugs results, what counted as a “positive”? For the cannabis-positive individuals, was it the active ingredient, delta-9-tetrahydrocannabinol (THC), that counted as a positive or did it include people who had the inactive metabolites present? The difference being that THC is only present in the body for one to three hours after use of the drug whereas the inactive metabolites can be present for days or even weeks after the person was ‘stoned’. Incorrect interpretation of analytical results can be misleading to those who don’t realise there is a difference. How about the 25% who “had used a combination of drugs, which may have included alcohol and/or cannabis.” What does that mean?

Secondly, saliva testing at the roadside – does New Zealand need it and should the Police be provided with these tests? The tests being used in Queensland currently only detect cannabis, methamphetamine (auch as speed, P) and MDMA (in Ecstasy). So saliva tests are not the silver bullet in roadside testing at the moment. Blood still needs to be collected to detect the presence of other drugs such as benzodiazepnies and other common drugs of abuse such as the opiates, methadone and cocaine. There is information ‘out there’ about how to fake or con a saliva test – you can’t fake a blood sample or hair sample.

Thirdly, impairment tests, which are not a “pass” or “fail” – they are a subjective interpretation made by a police officer based on a set of criteria with which they have been provided and trained to dispense and observe. The new law that came into place at the end of last year saw the introduction of impairment testing at the roadside, a move which is at least ten years behind some other developed countries, but better late than never. This is a tool that the Police can now use to determine if someone is impaired, particularly if a breath screening test is negative. Individuals are required to undergo an impairment test if the Police Officer “has good cause to suspect the consumption of a drug” (Land Transport Amendment Bill (No. 4), Explanatory Note). Unsatisfactory completion of the impairment test could be the result of a number of issues, not just drugs (tiredness/fatigue, new prescription medication, undiagnosed medical condition, etc. – all of these I have encountered before in drink and drug driving cases). The way to solve the issue is to have a sample of blood from the driver analysed. The results and interpretations will be key in a successful criminal case. The law does allow for the defence of a valid prescription for a controlled drug.

The legislation that introduced impairment testing has a final point in the Explanatory Note that states blood specimens taken for alcohol offences can be analysed for research purposes to enable a better picture of drug-driving in New Zealand to be established. I assume this means that there will be a mass of data available pretty soon – and we can expect a new report on the effectiveness of impairment tests in reducing drug driving.

To reduce or not reduce – that is the blood alcohol question Anna Sandiford Jul 28

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Several posts have got involved in the blood alcohol debate (examples being Blood alcohol, Categories of drunk and Wobbling into the road after a night at the pub….). Should NZ reduce the blood alcohol limit for driving a motor vehicle from 80 mg alc/100 ml blood to 50? The UK still has 80 in blood as the legal limit and we in NZ take a lot of what we do in our justice system from theirs.

One thing that has not so far been mentioned is that the NZ breath alcohol limit for driving a motor vehicle is 400 ug alc/L breath. This is established using a blood:breath ratio in the region of 2100:1. In the UK, this ratio is 2300:1, which means that the legal breath limit is 350 ug/L breath (there are plenty of studies that deal with this issue such as Cobb, P.; Dabbs, M., 1985: Report on the performance of the Lion Intoximeter 3000 and the Camic Breath Analyser evidential breath alcohol measuring instruments during the period 16 April 1984 to 15 October 1984. Her Majesty’s Stationery Office.   Jones, A., 1993: Disappearance rate of ethanol from the blood of human subjects: implications in forensic toxicology. Journal of Forensic Sciences, 38, 104-118, as well as various Home Office data.    The online version of Clarke’s Analysis of Drugs and Poisons will also be receiving an update from one of the world’s leading minds in this area but that will be next year so I can’t say too much more about it).

50 ug alc/L breath might not sound a lot but in a country like NZ that has a severe attitude problem when it comes to drink driving, it could make a difference.

Wobbling into the road after a night at the pub…. Anna Sandiford Jul 26

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Once again, alcohol-related stories are all over the media (Drunk driver haunted by night of shame; Joyce to review drink-driving loophole; ‘Humiliated’ barrister to plead guilty to drink-driving; Car death: ‘Any other kid, you’d be in jail’).  All of these cases, and most of the alcohol-related cases that are reported in the media, contain stories about people who were drunk and were driving motor vehicles – a catastrophic state of affairs at the best of times.

However, thought should also occasionally be given to those cases where the drivers are not over the alcohol driving limit but where people still die because they’re drunk.  I have worked on many road traffic cases where drunk pedestrians strayed into the path of an oncoming vehicle, were hit and killed or seriously injured.  The trauma of the event will never leave the sober driver but in many of these cases the ‘victim’ was too drunk to know what literally hit them.

Recent research in Forensic Science International Supplement Series demonstrates what we have all known for some time – that pedestrians belong to the group of road users with the highest mortality rate.  Basically, drunk pedestrians are classed as amongst those road users most at risk.  Work completed by Slovenian scientists shows that alcohol-positive pedestrians who died in road traffic incidents between 1999 and 2006 (n = 125) were predominantly younger men, who had a higher level of risk of a road accident, greater incidence of injuries and a shorter period of survival following a road accident – 92% of them died in the six hours after a road traffic incident, usually of head trauma [source: Prijon & Ermenc, 2009. Influence of alcohol intoxication of pedestrians on injuries in fatal road accidents. Forensic Science International Supplement Series, 1, pp. 33–34].

In one case I clearly remember, the pedestrian was a woman who was so drunk she ended up in the road in front of an oncoming motor vehicle.  My job in that case was to calculate her blood alcohol concentration at the time of the incident.  The unfortunate driver had been charged with death by careless driving but he said the pedestrian had just fallen into the road in front of him.  His lawyer was sensible enough to ask an alcohol expert (me) how drunk the pedestrian had been at the time of the incident: considerably, was the answer.  Enough to have significantly impaired her ability to co-ordinate her limbs (see Categories of “drunk”) – she probably literally stepped into the road in front of the car.

It just goes to show that even if people are responsible enough not to drive themselves home, they’re still a potential hazard.  And then there are the non-traffic incidents where people are so drunk they fall into or off things – but that’s a different story.

Momentarily alarmed… Anna Sandiford May 31

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Is it scary giving evidence in court?  Yes, when you notice a knife lying on a chair in the main foyer of the court.

I was in a south Auckland court today and to start with, the day didn’t seem anything unusual.  Whilst waiting around for the case to start, I glanced to my left and there, glinting in the fluorescent bulb light, was a knife.  It sat there, on the chair between me and a lady who was busy texting, seemingly oblivious to the knife on her right.  My vulnerability was suddenly starkly apparent and I casually glanced around to see if there was a police officer to whose attention I could bring this knife.  Nope. No police officers.  Was there any court security?  Nope, none of them either.  How about a plain clothes police officer or some sort of court official?  Nope, none of those either.

So what do you do?  It didn’t seem right to ask the lady if the knife was hers.  I was also suddenly aware that not all of the people who are milling around in a court foyer are necessarily very emotionally stable.  Certainly, there was at least one man rocking in his chair; on the other side of the foyer, two people were suggesting to each other in loud voices from close quarters that they would see each other in court (on opposite sides, I assumed); I was there on behalf of one party involved with an alleged assault matter.

So I did the only thing I could do – I went to the Fines Counter next door and advised them as calmly as possible that there was a knife lying about in the waiting room next door.  The hand of the counter clerk flew to their mouth in surprise and minor shock, followed by looking around to find someone to deal with it – the same problem I had: no-one.  That meant that the counter clerk had to go and retrieve it.  I bet that’s not part of the job description.

Although today’s minor excitement only involved an ordinary dinner knife, it was still capable of being used as a weapon and causing a fatal injury.  Many courts overseas have permanent court security staff with or without an x-ray machine and full body scanner and I’ve had my fair share of bag searches, but never in New Zealand.  I’ve always thought there was a case for having court security in every court, particularly after a man stabbed himself in the neck with a knife in Wellington District Court last year, but I’ve never been able to point to more than one violent occurrence (it’s a long story – but it’s in my book – due out next year!).  Now I know there is definitely a case for security staff, and possibly searching people as they enter the building.  And I’m back at the same court in a few days’ time….

How we behave when we’re drunk Anna Sandiford Apr 09

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Talking about lowering the blood alcohol limit in New Zealand to 50 milligrams alcohol in 100 millilitres of blood is today’s big story. I’ve been asked by lots of people over the years about how much alcohol drivers have to consume in order to be over the legal limit. Quite rightly, the ESR scientists indicated to the Science Media Centre briefing yesterday that it’s a function of height, weight, gender, food in the stomach (although that’s a contentious issue in England) and type of drink consumed. Thinking in terms of standard drinks is not helpful, particularly for smaller people, because a standard drink doesn’t take these things into account.
I therefore thought I’d review the drink drive blood/breath alcohol levels that I have seen over the years whilst working as an Alcohol Expert Witness (because I’m a scientist and I keep all sorts of data, just in case…).
The average blood alcohol concentration of men (n = approx 400) was 165, more than twice the legal limit of 80. The most common level was 138.
For women (n= approx 100) the average was 184 with the most common concentration being 154.
Overall, although women were less likely to get done for drink driving, they were usually more drunk than the men (although the highest blood alcohol concentration I’ve seen was a man, nearly 320 in blood).
The biggest thing I’ve noticed though is that people who drive at a level between 60 up to about 100 (in blood) are the ones most likely to think that they’re safe to drive. Reducing the drink driving level to 50 won’t change their perceptions. Will lowering the blood alcohol level to 50 increase the numbers of people who get done for drink driving, or will it force people to rethink what they’re drinking? In my opinion, New Zealand is a hard drinking nation and I think a zero alcohol level would be the best way to go.

Drinking, driving and Maltese(rs) Anna Sandiford Apr 09

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Lowering the NZ drink drive limit to 50 milligrams alcohol/100 ml blood is big news this week. Will the government do it? Is that low enough? Should we do as the Maltese do (according to Google anyway) and have a zero blood alcohol level for driving?
I’ve written reports for a couple of thousand drink driving reports, mostly for the Defence because in England and Wales there are three standard defences to drink driving:
1. Drunk in Charge – e.g. too much alcohol consumed and no taxi money left, fall asleep in the car, get woken up by a cop at 3.00am and arrested because, in theory, the driver has the keys in their control, they are in charge of the vehicle and there’s a strong likelihood that the driver will drive home when they wake up, which is not necessarily when they are below the drink drive limit. The driver has to satisfy the court they wouldn’t have driven until they were below the legal limit.
2. Spiked drinks – e.g. driver thought they were drinking lemonade when they were in the pub. As it turns out, someone they may or may not know had put triple measures of vodka in each of their five drinks of lemonade. Lo and behold, they’re over the drink driving limit when the get stopped at a Booze Bus on the way home.
3. Post incident alcohol consumption – e.g. crash the car, before the Police arrive swig half a bottle of brandy that happens to be under the front seat.

Some would say that the English are perpetuating the problem by giving people a chance to provide a defence to drink driving. In New Zealand, there’s none of that nonsense – if you’re over the drink driving limit there’s very little you can do to defend the charge (in terms of the defences available in England and Wales) but you can apply for a work licence. I wonder whether that doesn’t give people a false sense of security about drink driving because there’s a good chance (or a very good chance if you have a specialist lawyer and haven’t done it too much before) that you’ll get a work licence. But I’m making the assumption that drunk people think rationally, which is not the case.
Personally, I would support any move to make the blood alcohol level for driving zero. That way people don’t try to guesstimate whether or not they’re above the legal limit because in my experience, they’re usually wrong.

Judge a crime online Anna Sandiford Mar 23

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Here’s your chance to judge a real case and decide a sentence. The UK Ministry of Justice has just issued a press release announcing a website that allows the general public to hear the circumstances of a criminal case after a person has been found guilty at a trial and then listen to the information to help determine a sentence.

Although not directly related to science, this is an interesting resource that could have application in New Zealand. It would give people a chance to consider the information and gather an insight into how sentencing works, which would take some of the bias out of people’s views of cases, which are largely driven by information provided to them by the media.

Even though this is an English site based on English law and the Magistrates’ Court (equivalent of NZ District Court), it’s quite realistic in terms of the types of information that are heard. To run through the whole thing takes about 15 minutes plus 5 minutes to read the press release that contains a you.tube video explaining the reasoning behind the establishment of the site. I hope that as the site develops, they introduce more complex cases and maybe introduce some scientific evidence. Give it a try and see what you think: You Be The Judge (once it starts, you can’t skip backwards if you miss a bit but you can pause).

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….

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.

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