Expert Witness (4 page)

Luckily for me, I was offered both jobs and, even luckier, I took the job in Cambridgeshire. I say that not because the CSE job would have been bad, because in a lot of ways it would have been an excellent career move. I say it because after I arrived in England a mere four weeks later to take up said new job, I found out I was seven weeks pregnant. With pregnancy came a super-sensitive sense of smell and I just know I would have vomited on a crime scene if I'd taken the CSE job. As it was, it was a close call on other occasions, particularly a long-distance cannabis cultivation case in South Wales.

Part of the job of the independent forensic scientist in England and Wales involves frequent travelling from the office to scientific laboratories around the country to examine items previously examined by the prosecution's experts. The way the system works is similar to that in New Zealand. An enquiry comes in from a lawyer asking for a review of some scientific aspect of a case, usually the prosecution expert's findings. We provide an estimate of costs, which has to be agreed by the Legal Aid people before we can start work. Once we're advised that Legal Aid has been approved, we go off to the lab, look at the items, go home, write a report, send a bill and, some times, go to court to give evidence. Some times, it felt as if our job was just rubber-stamping what had already been done, at other times there was more to it. In this particular cannabis cultivation case the police had raided a property and seized a whole load of cannabis plants.

In a case where a cannabis growing operation has been raided by the police, not all of the plants will be sent to the laboratory for examination. As scientists, we rely on the
police accurately recording what was at the scene either by photographs, drawings and/or written notes. In some cases, scientists from a laboratory will go to a scene, but it depends on the particular case.

With this case only the police had attended the property. They seized dozens of plants from a hydroponic growing operation (a hydroponic operation is where the plants aren't grown in soil but are fed by nutrient-rich water pumped around their roots). Of those plants, they sent 12 to the laboratory for examination, each one sealed in its own brown paper sack. Once at the lab, the plants were taken out and dried, and most labs have a special drying room for this very purpose.

As I am sure many pregnant women will tell you, some smells are worse than others. For me, the assault on my nasal passages caused by walking into the lab's drying room was just too much. The sweet, heavy smell hit me like a smack in the face. I nearly passed out on the spot. The problem was that, at this stage, I didn't know I was pregnant. I just thought I was feeling rough, maybe coming down with a bug.

In the early days of my forensic science career, I went along to science laboratories as an assistant to my boss. Basically, he got to do all the good stuff and play with the exhibits while I had to write notes and keep up with his rapid narration. On this drugs case, it was just the same: he played with the plants and I wrote the notes. We were in that room with those plants for more than two hours. We had to examine them to check they were cannabis, photo graph them, check the other scientist's case file, reweigh the leaf material, reweigh the flowering head material, repackage every thing, chat with everyone my boss knew at the lab and stop for a cup of tea
in the staff canteen. By this stage I couldn't bear the smell or taste of tea — iced water for me, thanks.

After all this in a small, stuffy, windowless, airless room, trying to impress my boss of only three weeks, I was feeling decidedly pale. My skin was damp, my eyes were dry, my hair was clinging to my scalp, my conversation was at the level of grunting, my writing was illegible. Even my hands were rebelling; cannabis plants are hairy critters and when they're dry, they shed sharp little spines all over the place. As I was writing, the hairs, which were being scattered liberally by my boss's shredding of the packaging, were showered all over the writing area and the paper. The hairs were grinding into my skin as I wrote and were unbearably itchy. By the time I'd finished writing I was smeared with a fine dust of powdered cannabis.

As was often the case, we had driven to the laboratory separately. After an interminable amount of time, he finally zipped off in his BMW and I headed off slowly in my Ford Focus, slumped in the driver's seat like a bag of old spuds. I got about 10 kilometres down the road, still feeling vile, but also surprisingly hungry. I stopped at a supermarket, ate some food and then promptly fell asleep in my car in the car park for two hours. How to explain a late arrival back at the office? It's amazing the number of roadworks that spring up all over the motorway system, particularly if two different people are travelling back to the same place along two different routes …

As you can see, I took a somewhat circuitous and less-than-conventional approach to my chosen career, but it can be done
both more cheaply and more quickly. I do, however, always recommend reading around a subject before committing to it, particularly some thing like forensic science, which has a tendency to be surprisingly gruesome when you're least expecting it, so here are a few suggestions:
Henry Lee's Crime Scene Handbook
;
Stiff: the curious lives of human cadavers
by Mary Roach and
Death's Acre: inside the legendary ‘Body Farm'
by Bill Bass and Jon Jefferson (see reference section for full details).

Because so many people are influenced by programmes like
CSI
there is, as I've said before, a perception about forensic science — it's sexy, intriguing, indescribably useful and vital for case solving. So when people say they can under stand why I do it because of their impression from TV programmes, it used to throw me into a bit of a spin although now I realise it's a great way to get people interested in science and also a good way to start a conversation at a party early in the evening when no one knows what to say. To me, forensic science is science at its most basic. It's been stripped down to the absolute bare bones because that's what happens when you give evidence and that's how you should write a report — so that it's totally justifiable, easily explainable and can be understood by anyone. There's no question of developing a new technique and bounding into court to give evidence in the next appropriate case — the method has to be tried, tested, approved by one's scientific peers, published in the relevant scientific publications and so on. In fact, this is exactly what the recent US investigation into forensic science in the United States has found — that not enough of the forensic science being presented in court has been through the same peer-review hoops as science in the academic arena. I wouldn't even
think of trying to offer expertise and advice in a case with a method that wasn't tried and tested: I'd be torn to shreds by a good cross-examination and I'd probably never be instructed by the lawyer again. It would take a certain kind of barrister to allow such a gay-abandon approach to a case and at the end of the day, lawyers have their client's best interests in mind; they don't want to run any unnecessary risks. This is particularly so in criminal defence cases where many lawyers try to minimise the number of witnesses they call because, after all, it's the prosecution's job to prove beyond reasonable doubt, not the defence's job to prove innocence. Although some times I wonder if observers under stand, or want to under stand, that distinction.

Research science is a totally different game. It's about pushing forward the boundaries of science, getting into scientific and politico-scientific battles with colleagues and co-workers, competitive funding runs, and finding corporate dollars to fund risky research projects. Forensic science to me is the total opposite of all that. It shouldn't be about taking risks and pushing the boundaries of science because we are talking about a legal system that requires a standard of proof beyond reasonable doubt or, at the very least, on the balance of probabilities. If it's not reliable or repeatable, there will be problems even being allowed through the court room doors to give evidence, never mind the next step of having it accepted into evidence.

Keeping up with changes in forensic science and matters that are relevant is a mammoth task, particularly now that I'm running my own consultancy. I remember back in the days when scientific advancement in the media was pretty much
limited to one or two major items a year, or so my remnant teenage brain reminds me. We used to have a programme called
Tomorrow's World
. I think it was on Thursday evenings, probably after
Top of the Pops
, and it showcased the latest in popular science developments. One night, the presenters were clearly beside themselves with excitement about the new development they were showcasing. Usually, they had feeble-minded attempts at science revolutions, some of which seemed embarrassing to demonstrate (I shan't name names because that wouldn't be nice.) Tonight, though, they had a box on the table. It was a box with a glass-fronted door. The magic thing about this box was that it heated things with nothing more than the power of water molecule vibration. What they had on the table was — drum roll — a microwave oven! Look at that, audience! You can put some water in the microwave, press the button and voila! Hot water! And that was the science advancement for the
year
. These days, science is changing on a day-by-day, minute-by-minute basis.

I have a blog, which is syndicated to New Zealand's largest science blog network (Sciblogs.co.nz). Because I'm a member of Sciblogs, I feel compelled to explore things of relevance and report them. This means I spend a sizeable portion of my day trudging the web (surfing just isn't the right word — it doesn't involve skimming across the surface and it doesn't involve being by the beach), checking Google Alerts, checking Twitter, Facebook, news sites, science sites, online publications — the list is seemingly and probably literally endless, because it just starts all over again tomorrow. Some people love it — that much is evident from the number of blog posts they put up every week and the online following they have developed,
but some times it's so
exhausting
. Please bear this in mind if you read my blog — some tough trudging went into that last blog post …

In summary, it's been a long and winding road to get to where I am and the road ahead is no less wiggly. I just hope the next 20 years will be as interesting.

F
orensic science is a bit like love: it's a many and varied thing, some times it's the best thing since sliced bread, other times you wonder why you ever bother. Although that's where the similarities end.

As I said at the very start of this book, I want to give you an indication of how forensic science is applied in a practical sense and an idea of what the job involves. In order to do that, I should explain what the job actually entails. As with a lot of jobs, the only people who really under stand what I do are other people doing the same thing. Even people (non-forensic scientists) with whom I have worked closely for extended periods of time still only have a snapshot image of what I can actually do.
The reason for that is because I am instructed (legal term for being briefed) in cases for a specific purpose relating to that particular case; no single case provides the opportunity to showcase every thing my colleagues and I can do.

When I say I'm an independent forensic science consultant it's a bit of a mouthful but it's accurate, and that's important when your day-to-day job involves working with people who interpret words for a living. In a nutshell, my job is to make sense of science.

What I don't do is what they do on the TV. I don't even do the same job as forensic scientists who work for the prosecution or the police, and I certainly don't see dead bodies all the time.

However, what I've discovered while trying to describe my job is that it's nigh on impossible to generalise about what I do — if I break it down into interesting examples, I'd have to write an enormous book just to try to describe it all
and
cover every thing my job involves. The problem with descriptions of what I do is that the specifics of casework are very different depending on whether it's criminal, insurance cases, civil litigation, family court cases or one-off projects, or if it's for training or giving lectures, seminars, workshops and presentations, even though the basic scientific approach is the same. One of the roles scientists like me have is generally being the ultimate quality control check. If the scientific report and its background can withstand independent scrutiny then the work has been done well by the other side's scientists. It's usually the case that the work is fine, but there are times when the work isn't up to muster — and it's up to me to check it and report what I find. Simple as that. Other times, I consider alternative hypotheses presented by my instructing party. I
might also be the only expert involved in a case (such as drink-driving cases), but we'll come to all that later.

In general terms, the job involves reading documents, preparing reports, occasionally attending laboratories, occasionally undertaking original work, and giving evidence in court. Reading that last bit back, it sounds incredibly boring, which is exactly what a geology colleague of mine said recently when I gave a presentation to the local Auckland GeoClub. The thing is that, compared with pure scientific research, the application of science in a forensic context must seem unbelievably boring because it appears very simple. In reality, of course, it is anything but. If we look at what other scientists do then maybe you can see where it gets interesting. Scientists working in traditional ‘prosecution expert roles' are those who are usually undertaking original work and testing. One of the most interesting examples would be somewhere like the Defence Science and Technology Laboratory (DSTL) in England. In this sense, ‘defence' refers not to the criminal justice system meaning of the word but rather the ‘Defending of the Country' meaning of the word, and definitely with capital letters these days! Among their wide remit is dealing with chemical and biological terrorism and explosions. Their experts were at the scenes of the London Tube and bus bombings in 2005 as well being involved with retrieval and analysis of evidence that assisted in the prosecutions that followed. DSTL scientists test the likelihood of success of home-made bombs. If they're doing this work and someone charged with terrorism offences wants to challenge the science, then independent scientists like my colleagues and me are required.

I know a man who spends his time, among other things, training ex-soldiers in bomb detection. A company with which I regularly work has recently acquired a cadaver dog (a dog that detects cadavers, not a dog that is itself a cadaver). I love helping them out with training courses because it's so very interesting and entertaining. The people who attend the training courses are police officers, crime scene examiners, crime scene managers and forensic pathologists. Between them, they've seen every type of scene imaginable. One of the other course presenters has spent time in Eastern Europe and the Middle East examining war crimes and blood spatter patterns — not the sorts of stories that are ever casually recounted over dinner but an account of such a crime scene is entirely appropriate at an outdoor body recovery course. It's those sorts of stories that make me realise how far-reaching our work can be and why I enjoy being part of the training course; I always feel as though I've learnt as much as I've taught.

One thing that has resulted from TV programmes like
CSI
is an enormous interest in forensic science, because people think the job of a forensic scientist is as glamorous as it is portrayed on the screen. Not so. Some times it's extremely boring and it doesn't usually involve high speed car chases or being shot at. Scientists who work in more traditional roles for criminal prosecution laboratories can be quite restricted in what they do. A scientist who did a degree in chemistry might get a job in the drugs section of a prosecution laboratory, which means that for the indeterminable future they'll be opening evidence bags that usually, but not always, contain drugs. They'll apply the standard set of protocols (describe what you see, weigh it,
analyse it using standard methods or send it to someone who will do the analysis and send you the results), write a report, move on to the next case. The chances of someone in the drugs section (other than those doing analysis of clandestine drug laboratories) giving evidence is, in my experience anyway, much lower than working in other areas of forensic science. Let's face it, there's usually not much to argue about when it comes to identification of 10 kilograms of cocaine.

Biology graduates usually end up in the biology/DNA section where they'll process items and samples in a case then move right on to the next case. The main difference for DNA scientists is that they work in what are described as ‘clean environments', which means they're constantly changing lab coats, face masks, gloves, overshoes, trousers … it's a hugely wasteful industry in terms of the non-recyclable items, which are chucked out on a daily basis.

Most of what I do as an independent expert involves examining scientific reports. Again, that sounds incredibly boring.
Au contraire
: a scientific report that lands on a lawyer's desk is, metaphorically, exactly like an onion. From a distance, it usually looks lovely and has a smooth-looking exterior. As we all know, onions are made up of many layers, just like a scientific report. Each layer took time to grow, each of the layers supporting the overlying layer. At the centre of the onion lies the original item that led to the preparation of the report.

Just like a real onion, it's not until you pick up a report and have a good grapple with it that you can make an assessment
of whether it's good and solid or whether the skin's going to crumple at the slightest pressure. That's where I come in — as the onion specialist. A lot of lawyers look at the onion on the desk and try to pick holes in the outer surface without actually picking it up and seeing what's gone into making the onion the size it is. My advice is that when you've got an onion on your desk, get an onion specialist to take a good, sharp knife and cut through it to see what's inside. If there are bad layers under there, every thing over the top of it might be tainted and need throwing out.

Like the best onions, some scientific reports have few layers, are small, sweet and very good. Others, on the other hand, are large, multi-layered monstrosities that took a long time to grow and when you cut into them, they make your eyes water. Although many lawyers don't like to examine science too carefully in case they don't like what they'll find, in many cases it's possible to examine it without compromising anyone's legal position. I just always think that it's at least worth having a quick look to see whether you've got a good or bad onion.

While I know about lots of different sorts of metaphorical onions, real ones aren't my forté — people who know me know that cooking is not one of my strengths. However, my areas of scientific/onion expertise are diverse and varied, purely because of my background and training. It means my day job is far more fun because I like the unexpected — you never know what's going to arrive in the post. Like the day a pair of soiled knickers fell out of an envelope onto the desk — a very unexpected onion indeed. Luckily, it wasn't my desk. No, it was one of our personal assistants. She basically did all the non-scientific stuff in the office, including opening the post.
On this particular day, she slit the envelope with the letter knife and — plop — out they fell! A pair of pale pink, soiled knickers, with a small note and a business card. It seemed that someone, somewhere, had been cheating on her husband, who was a lawyer. He picked up what he deemed to be an offending set of underwear, stuck them in an envelope with a disgruntled note and sent them off to us for ‘analysis'. The problem with that sort of approach is that there are all kinds of issues about continuity of the item, accidental contamination of the DNA because of handling by our unfortunate PA and anything the knickers might have soaked up on their way through the postal system. After all, it was a cold, wet, winter's day, the envelope had been wet and the knickers were without any packaging save for said soggy envelope. Even if we did get a DNA result, what were we supposed to do with it? Without a reference sample from the disgruntled husband, we couldn't interpret the results.

Despite a few carefully worded messages left on the business card's phone number (one has to be careful with message wording — one never knows who might be checking voicemails), we never heard a single thing. That in itself leaves a problem. We now have a pair of ownerless knickers sitting in the office. We can't destroy them because they might be required as evidence. We can't get hold of the owner or the client because there's no answer on the phone or to our letters. What happens? In that case, I have no idea. As far as I know, those pink frillies are still in the office.

Independent expert witnesses are nothing without solicitors and barristers. Without them, we don't get any work. We rely on receiving full and accurate information from them because
our work can only ever be as good as the information with which we are provided. As the old sayings go,
rubbish in, rubbish out
,
you can't make a silk purse out of a sow's ear
and
it's quality, not quantity, that matters
. We receive our instructions usually in the form of letters because this is the legal arena and everything should be documented and recorded. It's important to remember at this point that lawyers have to act on their clients' instructions, no matter what the lawyer thinks about those instructions. Lawyers can advise their clients but the client doesn't have to take that advice.

It's always amusing when we receive bizarre instructions, which some times we don't under stand, and even the solicitors don't under stand. Take this letter we received in a drink-driving case, which included the phrase:
To the line and also lies showed a lower reading of H2.
Now, I know a fair bit about drink-driving cases but I had not the faintest idea what this was all about. After having read through the file, though, I could see where the problem had arisen. The breath-testing device that had been used was the Lion Intoxilyzer and the results of the two breath samples were 84 and 82. The sentence should have read,
The Lion Intoxilyzer showed a lower reading of 82.
When I rang the solicitor and read it to him, he said we had passed the test and he was just keeping us on our toes (and that he had a new secretary who'd never done legal work before and had never heard of a Lion Intoxilyzer).

Then there are the instructions that are in the sort of code the police use for describing events. In this particular case, a defendant had crashed into a street sign when he
failed to adequately negotiate a bend
. We were advised that, fortunately, neither the driver nor passenger was injured, although the
driver somehow managed to acquire a head wound when diving into a bush in an attempt to evade capture by the police. I was intrigued, and went on to read the full, bizarre series of events. The police described chasing the driver, on foot by this time, until they came to a corner.
As I rounded the corner, my colleague was partially blocking my view but I became aware of a pair of legs sticking out of the bush which we made a move to grab hold of.
As it turns out, the driver had panicked and jumped into the nearest bush when he was out of sight of the police. Unfortunately, it was a laurel bush and was very sturdy, so sturdy in fact that he couldn't get into it properly and couldn't get out of it again either. Luckily for him, the Boys in Blue were close by to give him a helping hand.