Expert Witness (21 page)

Luckily for me, my first experiences of fire cases were more encouraging than those of a colleague. He attended a fatal house fire and wandered nervously into the scene, trying to look as if he knew what he was doing. Fire scenes are littered with debris and it takes a while to see what you're supposed to be seeing. He found a fire officer in what had been the sitting room and asked him, in as professional a manner as he could summon, where he could find the body. The reply was ‘You're standing on him.' The poor victim had literally burnt to a crisp and was but a mere smear and collection of bone fragments, cloth and charcoal on the floor.

Unfortunately, footwear marks are not just found on floors or other inanimate surfaces; occasionally they turn up on people. There was a case once where a chap was found dead in a park in the early hours of an autumn morning. Shoes were seized from two suspects who'd been seen in the company of the deceased earlier the previous day. As is often the case, large quantities of alcohol had been consumed by all involved, so who knows what state of mind everyone was in when it all kicked off, as it were.

Photographs were taken of injuries on the head of the deceased and these were compared with the sole patterns and
the uppers of the shoes seized from the two co-defendants. The first defendant, for whom I was undertaking the review, said that although he was with the deceased and the co-defendant on the evening of the incident, he didn't strike any blows to the deceased.

As the independent expert, I was asked to consider the findings of the prosecution expert and whether the bruises on the victim's head could have been caused by either of the pairs of shoes seized.

When an item is used to inflict an injury on an individual, a contusion or bruise may result, or some times the skin is broken. Comparison of bruising patterns can be used to draw conclusions regarding whether a given item may have caused a certain bruise. In some cases, it's possible to identify characteristic features to connect a specific item of footwear with a specific bruise. Conversely, in many cases, the bruising is simply not clear enough for any comment to be made regarding the item that caused the bruising.

In this particular case, one pair of trainers had a sole with a sort of yin-yang pattern and the uppers were quite unusual — I'd never seen anything like them before and neither had the prosecution expert. The thing with cases like this is you then spend the next two weeks looking at people's shoes to see if you can spot another pair, but I've never seen one; maybe it's because all three people involved were from Eastern Europe and they'd been shoe shopping at home and brought back some thing interesting.

The second pair of trainers had a simple sole pattern of rhomboids and the structure of the uppers was completely different from the first pair.

As a result of my examination, I determined that the bruises on the head of the deceased could have been made by footwear attributed to the first defendant but the problem was that the laboratory database wasn't big enough to draw any real conclusions. Of significance in this case was the fact that the footwear had never been seen before by either the prosecution expert or me and the first defendant had already accepted that he'd been with the deceased and the co-defendant on the night in question. It came down to the likelihood of the marks being caused to the head of the deceased by either the first co-defendant or by someone else wearing similar shoes who happened to come along that same evening and kick the victim to death.

It was far more likely to have been the first defendant rather than someone at random so it came down to the fact that the first defendant said that even if he had been present while the deceased was on the ground, he might only have knocked his head with his foot by mistake and if he did knock his head by mistake, he only did it once.

This defence is kind of like the naughty schoolboy approach, of which a colleague of mine is particularly fond, which says,
I wasn't there when the window was broken but if I was then I didn't do it but if I did do it then it was an accident.
I guess it's about covering all bases.

I think what you should do now is go and look at the soles of some shoes.

Sock prints in casework are somewhat unusual because sock prints are usually just a general outline of the foot that
made them. If people are in someone else's house when they shouldn't be, they're usually wearing some sort of footwear. The most memorable sock-print cases for me have involved people being in a property when they have been invited or when they lived there. In normal circumstances, finding the sock prints of someone who lives in a given house isn't something likely to be of great interest. When it does get interesting is when the socks have some thing on them that makes them a little unusual, such as blood.

The two most interesting cases I can describe both relate to murders and both relate to bloodied sock prints deposited on floors.

The circumstances of the first case were that a woman and her boy friend had her boy friend's friend staying in their home with them. They had all been out drinking and when they came home, the woman ended up dead on the kitchen floor, stabbed with a kitchen knife. The boy friend (let's call him Mr Boy friend) and his mate (we can call him Mr Mate) were both charged with murder and each blamed the other for the woman's death. Mr Mate said that Mr Boy friend and his girlfriend had gone back to the house on their own and when he arrived at the house the woman was already dead.

The interesting thing at the crime scene was that the woman was dead on the kitchen floor and two sets of bloodied sock prints could be seen tracking through the house. One set was fairly average in size and the other was markedly larger. Mr Mate said that the marks couldn't have been made by him and they therefore must have been made by the deceased and her boy friend. That was relatively easy to sort out because the deceased had small feet and even allowing for the fact that
her test foot impressions had been made by rolling ink onto her feet and pressing her inked feet onto paper while she was lying on her back in the mortuary, her feet couldn't have made either sets of sock prints. So who did leave them?

Each of the defendants was asked to make test impressions, which involved them wearing socks, walking onto ink and then walking down a long sheet of paper. One set of prints in the house matched the size, emplacement and gait of Mr Boy friend. The other set matched Mr Mate. Mr Mate strongly denied any involvement but unfortunately for him, he had a peculiar arrangement of toes and foot outline. We knew this because a forensic podiatrist had taken a look at the test impressions and told us.

Once Mr Mate accepted that his bloodied sock prints were in the house he tried to explain them away by saying he returned to the house after Mr Boy friend had killed the woman and he, Mr Mate, had accidentally walked in some of her blood while he was trying to ring the police, which he didn't manage to do. Unfortunately, what really did it for Mr Mate was the fact that he couldn't explain why he'd taken off his shoes and the trail of sock prints didn't lead to the telephone — this was in the days before mobile phones were widely available. Instead, the prints led from around the deceased out into the hall, back into the kitchen, across the kitchen floor, onto the kitchen work top, out through the kitchen window, onto the outside windowsill, down the garden path, through the side gate, down the side passageway and along the pavement away from the house. Mr Mate was found guilty of murder for more reasons than just the sock-print evidence, but the prints helped. Mr Boy friend was also involved with the incident and his sock
prints related to how he had moved around after the woman had bled to death.

Another case in which I was involved need not be anonymous because it is that of David Bain. The sock-print aspect of the case related to the size of print a foot might make if it were clad in a sock that then walked in blood. It was accepted by the Crown and defence that whoever murdered the mother, two daughters and son was the same person who deposited bloodied sock prints in one of the rooms and part of the hallway of the house.

My role was relatively simple: to undertake tests with David Bain's socked feet to determine what size prints his feet would make after he walked in blood and after those marks had been enhanced with the same chemical used at the crime scene in 1994 by the Crown's expert. This evidence was important in the retrial because the Privy Council had referred to the sock-print evidence as being one of the reasons they considered a substantial miscarriage of justice had occurred.

By way of background, a forensic scientist and a police officer examined the carpets for the presence of blood. They detected a number of bloodied sock prints, made by a right foot, on the carpet leading from Stephen Bain's room, into Margaret Bain's room, tracking out into the hallway. The carpet on which the sock prints were located was not retained and as far as we know it went up in smoke when the house was burnt down.

The sock prints were on a dark-coloured carpet and a chemical called luminol was used to enhance them. Luminol reacts with iron in blood, causing a blue alien-like glow that
can last for a few minutes. In fact, when I was measuring the test sock prints, I remember glancing around the floor of the laboratory at the eerie scene of disembodied prints heading in all different directions and being surprised at how long the glow lasted. As the glow fades after five minutes or so, it's one of those lights that looks brighter from the corner of your eye.

Some of the sock prints at Every Street were incomplete but two were described by the forensic scientist who examined them as being 280 mm long,
that the print encompassed both the heel and the toes, that was a complete print from heel to toe
. This evidence he repeated:
The other prints that I detected with luminol showed the toes as well, taken from the top of the toes to the heel.

The simple question was whether or not David Bain's foot could have made marks of that size and description. Although David Bain testified in evidence at the first trial that he had gone from room to room after he got home, the sock prints were found in a place where the Crown case said Robin Bain would never had been on that morning. At the first trial it was accepted that the sock prints had been made by David although it's not clear why that happened. It could have been because evidence was given that:

A forensic scientist for the Crown undertook some bloodied sock-print tests in 1997 and 2007; the final results of these tests were described as follows:

In response to this work, the forensic scientist who had attended Every Street made a further statement saying that his description of
a complete print from heel to toe at 280 mm
meant that in the print he could see the toe area as well as the heel area, to differentiate it from other partial prints.

Hence the sock-print tests described in the Prologue. The tests we conducted used methods applied by the Crown's expert. The results of my tests indicated that David Bain's foot was too big to deposit complete marks 280 mm long. His feet are 300 mm long and he deposited luminol-enhanced marks that were, on average, 306 mm long. This was an average taken from a total of 22 prints, which ranged from 300 mm to 315 mm.