Please post your questions for this week in the comments section. At the beginning of next week, Dr Penny Haddrill will respond to the most interesting, useful and/or popular questions. Please ‘like’ questions posted by other learners if you are also interested in having these answered.
Firstly, thank you very much for all your excellent questions and comments again this week, I hope you are enjoying the final week of the course, bringing together all of the scientific evidence we have looked at as the case has unfolded. This week, your questions were almost all about the case itself, so I’m going to focus on this in my answers. In previous weeks I have tried to answer questions that are less directly related to the case so that your knowledge and understanding of the case develops alongside the evidence being presented to you, but since we are now nearing the end of the course I will try to clear up some of your issues with the case. Hopefully any remaining questions you have will be cleared up in the final big reveal of the verdict on Friday…
Firstly, throughout the whole course, a lot of people have asked about gunshot residue and whether any test for this could have be done in this case. In general terms analysing the gunshot residue could be useful, and in some case contexts could give you some useful information. However, there are some important limitations of gunshot residue evidence, particularly in this specific case. The first is that in any shooting, particles of gunshot residue are transferred onto surfaces near to where the gun was fired, including skin, clothing, nearby surfaces etc., but they are also lost very quickly. Many forensic laboratories will not accept items for examination for gunshot residue if they are collected more than a few hours after the incident took place, as it would be unlikely to produce any useful information. The second limitation, specific to this case, is that here we have a situation where two people were shot inside/around a vehicle, and so it is likely that there will be a lot of gunshot residue all over those people and the inside of the car. Mr Ward’s hands could be tested for gunshot residue, but if this is found then it could be explained by him touching his own arm where he was shot, touching Mrs Ward or touching the inside of the car. So whilst it might be possible to identify gunshot residue, we have to think about whether this would actually be useful investigative information.
Related to this, a few people this week asked about whether any other useful evidence was recovered from the gun. Ghadeir Karama and Daniela Courvoisier asked whether any fingermarks were found on the gun, and in previous weeks there have been several questions about whether any fingermarks or DNA could be recovered from the gun after it had been in water, and generally whether any other useful evidence was found on the gun. The answer in this specific case is no, there wasn’t anything else useful found on the gun. In general, it is not possible to answer definitively the question of whether it is likely there would be any useful evidence remaining on the gun after it had been in water. A gun may have been cleaned, or the person who used it may have worn gloves, so there may not have been any useful evidence on the gun before it went into the water. If there was fingermark and DNA evidence on the gun then this would have started to degrade once it went into the water, and this would be more likely to occur if there was motion of any sort, such as tides or winds moving the water around. Many components of fingermarks such as sweat are water soluble, as is DNA, and so these would eventually be washed away. The length of time it would take for this to happen would depend on many factors, including the length of time the gun was in the water, the type of water (e.g. freshwater or saltwater), and the amount of the material that was transferred in the first place.
Another question that was raised a few times was about mobile phones. Both Marsha Snodgrass and Cheryl Thomas commented on mobile phones in this week’s questions, and several others of you have mentioned this in previous weeks. As you know, this case is based on a real case, and that case occurred in the 1980s, so there were no mobile phones involved. When we developed this course we tried, for the most part, to replicate what happened in the real case as closely as possible, to give you as realistic an experience as we could. For this reason, Mr Ward did not have a mobile phone. However, it is worth noting that if this case had occurred more recently and mobile phones had been as widely used as they are now, the investigators would have been able to get a huge amount of information from Mr and Mrs Ward’s phones, either using triangulation to determine where the phones had been located, or by accessing phone records to see who the individuals involved in the case had been communicating with.
Similarly, in answer to Juan Carlos Alvarez’s question about CCTV at the restaurant, as CCTV cameras were not so widely installed in the 1980s, there was no CCTV evidence available in this case.
You will note that when we introduced Mr Dougan into the case, he used a mobile phone, as we had updated this part of the story to reflect current times better. We have used a little bit of artistic licence in places to make sure that we are able to introduce you to the different types of evidence that we wanted you to see. For example, when it came to Mr Dougan giving the police a false identity, some of you asked why the police didn’t take his driver’s licence or note the registration number of his car. In reality the police officers would have done that, but by including this aspect of the storyline we were able to build in the investigative aspect of looking for fingermarks, and the searching of these against the database resulting in a new lead in the case when they were found to be linked to another identity. For the large number of you who asked about the timing of Mr Dougan’s fingerprints being matched with Nigel Lloyd’s prints on the database, there wasn’t anything particularly significant about this, and there wasn’t any breakdown in procedures. This just reflects the reality of these types of complex investigations, in which investigators have to deal with backlogs in forensic laboratories and it simply takes time to get evidence processed through the system.
Caroline Thomson asked about the amount of blood inside the car and whether a head injury would be expected to produce a lot more bleeding than is seen in this case. The amount of blood that would be expected at a scene depends on a lot of factors, including the mechanism by which the blood was shed. If someone is beaten repeatedly, for example with an iron bar, the blood vessels at the surface of their skin will be damaged and their heart will pump blood out through the damaged areas. If someone is stabbed and an artery is damaged, there will be a very forceful spray of blood from the arterial pressure up until the point that the heart stops and a victim dies. A gunshot to the head with no exit wound will result in instant death and so does not produce an injury that will bleed dramatically. We would therefore expect to see a relatively small amount of blood dripping from the wound, as is observed in the bloodstaining on Mrs Ward’s arm and the car seat.
One other subject that came up a few times was toxicology, and Rita Sumano González and Hedley Quintana asked about this and whether drugs analysis could be carried out once the drugs had been consumed. Samples of blood, urine and hair can be taken and examined for the presence of drugs, and in a post-mortem other samples may be taken, such as the stomach contents or the vitreous humour of the eye, which is often used when bodies are very decomposed. Solid tissue samples can also be taken, including samples of the brain and liver. This analysis of drugs in biological samples is known as toxicology, and Brian Scobie correctly pointed out that there was no toxicology report on Mrs Ward reported in the case. Toxicological analysis can produce very important forensic evidence, and this is one major area of expertise that forensic scientists can specialise in. Unfortunately, we simply did not have time to cover every type of forensic evidence in six weeks, and so it was not possible to include toxicology in the course at this time.
John Bogie also mentioned the time discrepancy relating to the waiter’s evidence, and this has been raised in previous weeks. These time conflicts really just come down to human nature, as it is completely natural to not be able to remember to the hour exactly what you did on a given day. Timing inaccuracies in cases are to be expected, and our reconstruction of this case deliberately reflects the uncertainty over timings that investigators have to deal with in reality.
There were also a lot of questions about what Mr Ward said in interview with the police, what Mrs Ward knew about her husband’s affair, was an insurance policy taken out on Mrs Ward, etc. We wanted to focus very clearly on the scientific evidence in this case, and the way that forensic science was used to aid in the investigation. We therefore did not include any information about these types of questions as it was not within the scope of the course.
Finally, one question that has been asked by several people throughout the course is whether the material will remain available for you catch up on anything you missed, or to come back and look over again. This was asked by Jean Day and Ailsa W this week and lots of people have asked the same question in previous weeks. The answer is yes, the material will be available to you indefinitely, so please feel free to come back and go through the material again, or look at things in more detail if you want to.
All that remains now is to say that I hope you enjoy the rest of the material in Week 6. The video revealing what really happened will be made available at 16:15 BST this Friday, 27th May, and we are asking you to vote up to 16:00 BST on Friday for whether you think Mr Ward is guilty or not guilty. We really hope you will take the time to vote, and we would love to see lots of responses. I would also encourage you to vote according to your analysis of the evidence, and not on your gut feeling. This week we have been looking at a logical system for bringing together evidence and analysing it and thinking carefully about what it means from a scientific point of view. You should therefore focus on the science, work through it all logically and base your decision solely on what the evidence tells you. I really hope you have enjoyed the course, it has been a real pleasure interacting with you and reading all your comments. I have really enjoyed seeing how interested you have all been in the case, and how much discussion you have had about it each week.
Thank you very much for joining us for the Introduction to Forensic Science MOOC, and don’t forget to cast your vote before 16:00 BST this Friday!