What is the focus of your laboratory?
Forensic science — we carry out forensic casework examinations and report to the criminal justice system. Part of that work involves loading profiles to UK and Scottish DNA databases. In order to load to these databases we require approval from the United Kingdom Accreditation Service (UKAS) and the NDNAD Custodian Accreditation Service (CAS).
We are now part of the newly formed Scottish Police Service Authority (SPSA) which has brought together the four Scottish Forensic Science Laboratories, the Scottish DNA Database, Scene of Crime Examination Units, and Fingerprint Bureau under one umbrella as well as the Scottish Police College and several other functions. Our unit is SPSA Glasgow, but we provide service to the whole of south west Scotland. However, most of the casework comes from urban areas and predominantly Glasgow.
SPSA Forensic Services, Glasgow consists of approximately 300 people who deal with forensic science, scene examinations, and fingerprint identification. The laboratory is divided into biology and chemistry. The biology unit contains about 50 people and has 2 sections: a general biology section which deals with the examination of items for body fluids, blood pattern analysis, etc, and our DNA section which deals with DNA profiling of casework and database samples and loads data to the Scottish and national databases. People rotate between databases and casework on a monthly basis.
All the people in the biology unit have a degree or equivalent qualification, but not necessarily specializing in forensic science. An honors degree in a relevant subject is normally required and a Masters degree in Forensic Science may give you a better chance of obtaining an interview. In forensic science in the UK there is much greater emphasis on competence rather than solely relying on qualifications. Having a Ph.D. or BSc. on its own isn’t good enough. It’s always a good idea to write to your nearest forensic science laboratory to get shown round – see if it’s what you want to do and get your face known. Student attachment to do a project can help too.
Do you have any ongoing collaborations?
This is very much a functional forensic lab; we don’t currently have much of a research and development capacity. We have people that ask: how do we solve that murder or that rape - not research projects. However, SPSA has entered into an arrangement with universities to provide research facilities to the new organization. For instance, we take MSc. students from Strathclyde University to do MSc. projects and we have one just now doing a DNA project. The SPSA wants to initiate collaborations with academic institutions for development that cannot be undertaken in our labs. Not just DNA forensics – also drug analysis, for example. Collaboration with Universities may be the way forward in terms of new development. The most important thing we need to develop is a more standardized approach across the country.
What is your scientific background? Were you always doing forensic research?
My scientific background is completely in forensic science. I started in this lab at 17 as a lab assistant. My employer, Strathclyde Police, funded seven years part time study for me to get a degree qualification in microbiology at Paisley University. There was not a degree in forensic science at that time.
I came here at 17 because I was studying at night school to become a medical lab scientific officer and the work here was to get me the relevant experience. I was offered a job as a medical lab scientific officer, but the then head of the laboratory offered me the chance to stay here and get my qualifications.
That was well before DNA analysis appeared in Forensic Science! On a typical day back then the most technologically advanced analysis I would do was blood grouping.
Examination of articles for body fluids hasn’t changed a great deal, but back then we could only carry out blood grouping and we mainly focused on blood samples. Saliva and semen were not easily amenable to blood grouping so success rates were very low. Also there was a lot less casework in those days. There was nothing like the same degree of violent crime – it’s simply down to the number of offences.
In 1989, Ian Hamilton and I set up the first forensic DNA lab in Scotland and went for training at Cellmark Diagnostics in Abingdon. DNA in forensics was still relatively young then as Alec Jeffreys had only published his work on DNA fingerprinting in 1985.
In 1990 when we opened the lab, we were only doing large body fluid stains or samples due to the need for good quality intact DNA. Due to these limitations in size of sample, we were doing 50-100 cases a year. These were analyzed with Jeffreys’ multi-locus probes. Within a short period of time (1-2 years) we realized that the single locus probes (also from Alec Jeffreys) were more sensitive, allowing us to use smaller samples and do more cases. We could then push up the cases to 200-300 per year. However, there was still no analysis of the size of samples encountered in routine casework today.
It took a lot longer to process a sample back then. After the Southern blot, we had to slide the gel out of the platform and really weak samples were left in a freezer for 3 weeks! Then we had to strip the probes and repeat. For five probes you were looking at 15 weeks! However, for good samples that time was cut down considerably. It’s seems primitive now when you look back at it!
The next watershed was the introduction of PCR. In 1994 we started using DQ alpha: a single locus marker with discriminating power, but you could analyses samples that were too small for blood grouping and get a result.
In 1995, we began using Quad, a 4 locus STR system developed by the FSS. More loci were added incrementally: SGM (6) and SGM+ (10).
In 1994 we switched from Phenol/Chloroform to Chelex extraction partiallybecause of cost but primarily lab safety issues. We have not used Phenol/Chloroform since then. For DQ alpha, Quad, and SGM we used Chelex and then with the switch to SGM+ we moved to QIAGEN Kits to improve the quality of the purified DNA.
What are the biggest challenges for your laboratory?
Coping with the increased throughput in volume crime, such as house break-ins, car crimes, etc. Traditionally DNA analysis in the early 90s was viewed as the domain of serious crime, but due to the increase in sensitivity, there are thousands more cases that are amenable for DNA analysis.
How do you prioritize them?
Serious crime is still our priority, but we are conscious of the fact that volume crime affects most people. Almost everybody has had their house or car broken into or knows somebody that has. It’s a very important service to the public. There are a great many cases with volume crime that can now be taken on due to DNA. In the burglary type crimes, often the Police only have a few avenues to consider - somebody saw it happen and they can tell you who did it, there are fingerprints and there is DNA.
Do you see the CSI effect?
Yes, both from police and jury. They’ve been given an unrealistic expectation. We think what we do is pretty clever, but not as clever as what TV producers think we can do.
Please envision molecular forensics 10 years from now: which technologies will be around, what kind of data and information will be derived?
In 1992 we didn’t even anticipate PCR and PCR would revolutionize forensic science. The holy grail of forensic scientists who work in this area is to have a testing regime that gives you a highly discriminating profile and to have the facility to test that same sample and identify which cell types are present: I’ve got your DNA from a crime scene and I want to say that those are skin cells. Those are the questions we get asked in court – where is it from, how long has it been there, and how did it get there.
Do you think you’ll be able to do that in 10 years?
Yes – I know there’s work with RNA to identify what types of cell types are present, but that type of work needs to become synchronized with obtaining an STR profile. The same extract needs to be used for all these different tests. If you’ve only got a small blood stain you want to get all the information from that small stain. There is also the issue of obtaining DNA profiles that tell you about someone’s physical characteristics. That’s got implications for ethics and society. I think physical characteristics could be used. We have a big concern about terrorism at the moment and that might be a big driver for the introduction of data that informs you of the physical appearance of people in the future.
In terms of identifying a person, there are two ways of doing it: You either have a sample from a crime to compare to a sample from a suspect. Or you have a sample that predicts what someone looks like. But the science behind that would have to be completely reliable otherwise you would miss the person you are looking for.
The availability of intelligence databases is the most recent landmark in forensic DNA analysis. The number of crimes that are detected using DNA databases is incredible.
Do you see that becoming more international?
Yes, but I don’t foresee there ever being a European Union database, although police forces do have the facility to ask other countries via Interpol to carry out database checks. The requirement for an international search becomes more important, for example, in the south of England due to the number of international visitors. In Scotland, most suspects will be from Scotland whereas in central London the suspect could be from a number of places. Our databases help us to solve a very significant number of crimes.
