Sifting through the evidence
Forensic scientists can do more to assist defence barristers than simply analysing the evidence, Darise Ogden discovers
Looking for evidence in pollen, blood, broken glass, drugs, sock and shoe prints – it’s all in a day’s work for independent forensic science consultant Dr Anna Sandiford. And while she could well be the star of her own Bones spin off, Sandiford, like all forensic scientists, is quick to disabuse me of my CSI fantasies. “It’s never as good as it looks on the telly,” she says. “We don’t go out to crime scenes in our very nice tailored suits with high heels and lipstick, and squat down in the dirt and go, ‘Oh look, I’ve found the main piece of evidence’, and rush it back to the lab, and have it solved in half an hour.” I try not to look crestfallen.
A prosecutor friend once told me that he often has to point out to CSI-infected juries that it is not like their favourite forensic television series. Unfortunately, in most cases, DNA is not left willy-nilly all over a crime scene. But it’s not just juries who have fallen victim to “CSI syndrome”. Sandiford says she’s also had to remind defence counsel in England that it’s not like CSI – as they’re going into Court.
So what is it really like?
Evidence collection is like a chain, she says, and it’s very structured. First, the crime scene specialists will visit the crime scene and will look for and collect items for examination. The items are taken back to the lab, where they are looked at, and decisions made about what will be done next. For instance, she says, if the item is a pair of blood-stained jeans, also containing dirt and fibres, a decision has to be made as to which of the experts it should go to first. Because, unlike CSI, the analysts in a real world lab are not generally all-rounders. Instead, forensic scientists will specialise in a particular area such as DNA, or blood pattern analysis, or toxicology, etcetera.
Once the item has made its way through the various experts, then the item will be looked at by technicians who will collect the evidence. The results will then go to a scientist with experience in writing reports and giving evidence in Court, and he or she will interpret the information extracted from the item.
At each stage in the process, everyone is accountable for everything they do, she says. Everything can be disclosed.
Working with the defence
Although Sandiford does a lot of work for the prosecution in England, in New Zealand, her main role involves providing case review services for the defence. Rather than analysing the evidence, she interprets it, explaining what reports provided by the prosecution’s forensic experts really mean. She looks at the file as a scientist, and from the way the statements are written, can identify whether or not something needs to be addressed or investigated further by the defence. And where that something falls outside her realm of expertise (for instance, she is not a DNA expert), she can access her international network of experts to find someone who can provide the defence with the skill they need to uncover what could be vital evidence in the case.
She can also translate the science. “There are certain phrases that scientists use to say things because they have to be structured in a certain way, and unless you realise what they’re saying, sometimes the subtleties can get missed,” she says.
Sandiford also goes back to look at the original source documents – the job sheets, the police notebooks. She looks at continuity in respect of items of evidence: “What’s happened to that item, has it been packaged correctly, why didn’t they seize this, that, and the other.”
Her caseload is varied. In addition to her case review work, she can provide expert analysis on the areas in which she is herself an expert. She can, and has, advised on opium, and cannabis use and cultivation– whether x amount of plants really can be argued to be for “personal use”. She is also an expert on drink driving, and alcohol consumption. In respect of the drink driving cases, which in England attract three defences that are not available here, she has advised insurance companies in cases where the police have not attended as to what somebody’s breath alcohol level might have been at the time of the incident.
With respect to the alcohol consumption cases, she has been briefed in rape cases where both the defendant and the complainant have been drunk. It’s a question of how drunk were they, she says. “I can’t say whether they could consent or not because that’s very individual, but I can say, ‘Well, if she’d consumed this much, she’d be this drunk, or if he’d drunk this much, he’d be this drunk’.”
Sandiford also does glass cases – anything where broken glass might be – and sock and shoe prints. Sock prints can tell you the kind of weave somebody had on their feet, she says. If they’re left in blood, then using various enhancement techniques, she can get an idea of the length of the foot, its distribution, its outline. “There have been a few cases where people have had a foot deformity which has been picked up in the outline, and it’s a very unusual thing, so it’s likely to be them.” Shoe prints on doors that have been kicked in, for example, can provide quite a lot of information: the general size of the shoe, and the patterns on the shoe’s sole. “You are likely to have patterns on the bottom of your shoes that are unique to your shoes, and if you can see those in a mark, is it conclusive? You can say that I’m pretty happy that that pair of shoes caused that mark, and that individual then has to account for how their shoe mark got on the door when they were 300 miles away.”
Raining pollen
Another of Sandiford’s areas of expertise is pollen analysis, a fairly rare discipline. There are only about six experts worldwide, and three of them are based here in New Zealand. There are two aspects to it, she says.
The first is the use of pollen to confirm or dispute an alibi. By analysing the pollen found on a complainant’s and a defendant’s clothing, she can help ascertain whether a defendant was in the same vicinity as the complainant. For instance, if a rape occurs in an alley where a particular type of pollen can be found, if the defendant says he was never there, but the pollen has been found on his clothing – then, you may find your client has a problem with his alibi.
Analysing the pollen found in the nasal cavity of a body can also assist in determining where victims took their last breath – ie the place where they died. Not always, of course, but in some cases, it will, and it has.
Palynology, as it is called, can also be used to track the provenance of drugs as they move around the world. Plants such as cocaine, Sandiford says, have leaves that attract pollen. “Pollen literally rains out of the air, it’s called ‘pollen rain’,” she explains. “It lands in an area and it gets collected on the plants, and it goes through the same process as the cocaine, and it’s still present in the cocaine when it’s seized.” This assists in identifying where the cocaine is likely to have originated.
A duty owed to the Court
Sandiford will provide scientific advice or case review services to whoever asks the questions – prosecution or defence. However, if you’re after someone who will provide you with the answers you want, she is not your forensic scientist. “My duty is to the Court,” she says, “not to those instructing me. So if I do some work, and the people instructing me don’t like the answer, that’s how it is.”
It can be a challenge, especially when you’ve got people – your clients – pushing you, but she says, you’ve got to push back. “I’m a scientist,” she says. “I was trained to analyse things, interpret them, and report the findings in a non-biased way. That’s what I’m supposed to do.” Scientists should function on the basis of their scientific integrity. “If that’s compromised, then that’s the end of it, really.”
Of course, if a scientist were to fold and give into a client pushing for a particular answer, one would have to worry about just how effective he or she would be in the witness box and whether the evidence would stand up to cross-examination.
Working as she does for the defence, Sandiford knows that often the work she does will never see the light of day – especially where she’s advising her clients that the evidence is all pointing to the fact that their clients may be guilty. But it’s important for defence lawyers to know what the evidence is saying – “it’s the best way to move their case forward”, she says.
Dr Anna Sandiford can be contacted on 021 023 58982, or sandiford@fsrl.co.nz. For more information, visit www.fsrl.co.nz.
NZLawyer, issue 107, 6 March 2009