ABC Radio National: The Buzz 31 July 2004 - Sleuthing with Synchrotrons
[This is the print version of story http://www.abc.net.au/rn/science/buzz/stories/s1165692.htm]
Program Transcript
Anne Delaney: Gidday, I’m Anne Delaney welcome to The Buzz where we’re donning our trench coats to sleuth with a synchrotron.News story: When Japan’s top crime fighter stepped out his door this morning an assassin lay in wait. Only last November Takaji Kunimatsu warned gun crime was threatening the very foundation of Japanese public order. Despite numerous threats against the National Police Agency and metropolitan police since raids on the religious cult Aum Supreme Truth began nine days ago the man heading the investigation had no bodyguard. As Kunimatsu made his way to a car four shots from about 30 metres away were fired into him, three lodging in his body and a fourth passing straight through. Police said it was “a carefully planned and executed crime”.
Anne Delaney: Nearly ten years after Japan’s chief of police was shot, four suspects were recently arrested in connection with the crime. The evidence that led to the arrests is reported to have been identified using the world’s most powerful synchrotron – Spring 8. The brilliant fluorescent X-rays from the Spring 8 allegedly found tiny traces of metal on the coat of one of the suspects. The same traces are reported to have been found on the gun used to shoot the police chief.
Akito Kakizaki: Spring 8 synchrotron is a facility with high brilliance light source. The light is coming out from the accelerator with 8 GEV energies. With that kind of energy we can get sufficient intensity or high brilliance X-ray from the accelerator. If we irradiate material with these X-rays we can characterise the materials or decide what amount of atoms are included especially for small amounts of materials where we can distinguish every impurity inside.
Anne Delaney: So each element or each substance has its own impurities and you can actually identify the impurities of any element?
Akito Kakizaki: Yes that’s right and we can exactly determine or distinguish where the material is produced or what the origin of that material is by analysing the distribution of the impurities of course.
Anne Delaney: Because each element, depending on where it originated from, or how it was transported for instance, will always be different?
Akito Kakizaki: Right, that’s right. They can identify the impurities, not only the nature of the material but the impurities, and with such high brilliance X-ray they can identify the very small amount of impurities.
Anne Delaney: Akito Kakizaki isn’t involved in this particular case but he’s a professor at the University of Tokyo specialising in synchrotron analysis. This isn’t the first time a synchrotron has been used in forensics. Six years ago the Spring 8 synchrotron identified evidence that helped convict a woman accused of the Wakayama curry murders. In 1998 63 people were poisoned during a Japanese festival - the curry was laced with arsenic. Four people died as a result. The Spring 8 synchrotron matched the impurities of bismouth and antimony, found in the arsenic in the curry, with a tiny amount of arsenic in the woman’s home. The woman is however appealing her case in Japan’s High Court and I should add, a couple of days ago, Japanese police released the four suspects accused of the 1995 shooting of the police chief.
So, just how reliable is the evidence produced by a synchrotron? There are over 70 synchrotrons currently operating or planned in the world – about 20 of them in Japan. Australia has one under construction in Melbourne which should be operational by 2007 and crime fighting will initially be one of its priorities. As well as being able to analyse extremely small pieces of evidence, as small as ten nanometres - that’s ten to the minus 9 metres - synchrotrons are very fast. They accelerate electrons close to the speed of light and unlike a lot of forensic techniques they don’t destroy the evidence. But they’re huge constructions and extremely expensive. Most are at least the size of a football field with 30 to 40 beam lines radiating from them. Dr Bill Skinner is a senior research fellow at the Ian Wark Research Institute at the University of SA.
Bill Skinner: Conventionally forensics deals with, for the most part, the examination of very small particles - small pieces of evidence like fibres from clothing, paint fragments, glass, very small traces left by fingerprints etc. Now with a synchrotron, because it’s got such a bright source, you’re able to look at much, much finer detail. So the material that may not have been considered evidence before hand, might be revealed by the use of a synchrotron. Some examples of that might be very fine glass particles that are found in the clothing of the hit and run victim, trying to match that to the glass found in the headlights of a suspect car. Individual fibres that might have inks on them left over from a forged signature for instance, or latent fingerprints that may be found on various materials, even tabletops, paper or other pieces of evidence.
Anne Delaney: So essentially all of these elements like glass or sweat or other chemical residues for instance, they’re identified differently by different aspects of the synchrotron?
Bill Skinner: That’s correct. You can look at either the inorganic components which are the elemental compositions, or you could stick with the organic components which might be skin oils for instance if you’re looking at a latent fingerprint, or various other organic materials that are left behind by the presence of a person and/or thing.
Anne Delaney: Dr Bill Skinner. In the United States the FBI is already using synchrotron analysis and at the Advanced Light Source, the synchrotron at the Berkeley Lab in California Dr Michael Martin runs one of the beam lines as they’re called. He’s using infrared rays from the synchrotron to study the sweat from fingerprints.
Michael Martin: The fingerprints that you see are mostly composed of sweat. Some of the oils and some of the other chemistry that’s in sweat is what’s left over there and so of course most people know fingerprints in terms of just seeing the swirls and patterns on them and trying to match that up to somebody else’s swirls and patterns, but what we’ve been studying is trying to get a hold of the chemistry that’s coming out of this sweat and trying to understand if we can learn something about the person that left the fingerprint more than just you know what the swirl pattern is.
Anne Delaney: And what have you found?
Michael Martin: Well so far we’re at the really early stages of our study, and so we don’t have a whole lot of conclusions yet, but we found some intriguing things. We can for example see significant differences between children’s fingerprints and adult’s fingerprints primarily because as you go beyond puberty you start producing many more oils on your skin and so that shows up in the fingerprint quite nicely. So we can distinguish fairly easily between just a little tiny bit of a fingerprint you can see whether it came from an adult or from a child. The children’s fingerprints disappear fairly rapidly – you know most children’s fingerprints are made up of mostly just water and little bits of material that’s in their sweat but it’s primarily water so it evaporates fairly quickly. So especially if it’s a fingerprint on a car that’s on a hot day it’ll disappear within hours sometimes so it’s really hard then to go back and find that fingerprint and use it for identification purposes or even see that there was a child in that car for example.
Anne Delaney: What other information have you found about the differences in people’s fingerprints using infrared synchrotron?
Michael Martin: Well the other things we’ve been finding hints of are when people are on different medications or if they’ve had alcohol in their system things like this. You’ll see a lot of that coming out in the sweat as well and so you’ll see people that are on a high protein diet which people are doing now, and that causes a lot of ketosis. So you see a lot of ketones coming out of the fingerprint for example. And so you can kind of say something about what’s going on in the chemistry of the person in terms of either disease states or medications or things they’ve been ingesting lately. And then the other thing that we’ve really found nice is looking at these little particulars that are left over, we can really zoom in on just a little tiny crystal or tiny speck of some particle that somebody’s been handling and we can get a pretty good idea of what that particle is.
Anne Delaney: And so the technology that you’re working with do you think that that could really be an aid in field work when it comes to forensic cases?
Michael Martin: It might be. You know we’re just at the beginning stages of this and so it is a possibility that seeing smaller amounts of samples and certainly when you have very small partial fingerprints for example, when it’s not big enough to identify the traditional way, we can be able to enhance the seeing of what is left on that fingerprint. Like in these children’s cases you can kind of enhance what’s there to be able to just see the pattern at all and then secondly you know if there’s some chemistry that’s unique to that person, or more likely if they’ve been handling something at the time, you can see residues of that that are left over in the fingerprints. If there’s a little gunpowder residue for example you could know that that was the person holding the gun. You know, something along those lines.
Anne Delaney: And in particular, partial fingerprints, is that where it’s really going to help us say for example at a bomb site for instance?
Michael Martin: I think that’s really possible yes because the partial fingerprints are just not quite good enough to do the traditional matching with, unless you’re lucky enough to get right in the identifying region. Everybody’s fingerprint kind of looks the same if you just take only a millimetre of it. And being able to then actually pull out something about the chemistry of that person and being able to at least say well it wasn’t this whole group of people and it was probably one of this group of people – that at least is a good start. And then again if there’s other things left on the fingerprint that we can also identify then maybe piecing all that together will really be useful.
Anne Delaney: Dr Michael Martin from the Berkeley Lab in California. I’m Anne Delaney and we’re sleuthing with synchrotrons. Now just imagine what Sam Spade could have done with one of the other technologies increasingly being used to crack criminal cases – time of flight secondary ion mass spectrometry – TOF SIMS is what the experts call it.
Bill Skinner: TOF SIMS basically involves an ion beam which is pulsed onto the surface of a sample and the subsequently objected secondary ions pass through a time of flight analyser so that their masses are recorded. Now the pulsed ion beam is also scanned or rastered as we say across the surface so you can actually get an image of the surface in terms of its chemical content.
Anne Delaney: Dr Bill Skinner – he’s a Senior Fellow at the Ian Wark Research Institute in Adelaide where they are using TOF SIMS to analyse human hair. Hair is exposed to all sorts of contaminates shampoo, conditioner, sweat, skin oils so its surface is quite complex.
Bill Skinner: One can glean from time of flight SIMS, if you’re very careful, the trends in isotopes. So for instance one can look at say the sulphur isotope content of a human hair and gauge something about the diet of the individual the hair came from. Apart from the isotope work one can perhaps identify whether a person has been exposed to pollutants. For instance we have looked at hair from lead smelter workers at Port Pirie in South Australia and tried to compare what we can measure from the internal lead content of the hair with blood assays of lead. Other things have been looked at in human hair, not necessarily just with TOF SIMS but with other techniques as well. Apart from diet also certain indicators of disease, vitamin or element deficiencies in the diet for instance and also the exposure to organic pollutants. One particular study we’re undertaking at the moment is to see whether we can detect nicotine in human hair and be able to determine whether the nicotine has come from ingestion or inhalation or whether it’s just contamination. So you could see the advantage of being able to tell whether someone’s just been exposed to passive smoke or has been smoking themselves.
Anne Delaney: So in terms of forensics you could actually develop quite a detailed profile of someone simply from their hair?
Bill Skinner: That may be possible and we’ve developed some techniques for comparing the outside of a human hair which is exposed to the environment and all kinds of contamination and the internal components of the hair which will be more indicative of ingestion and bio-availability. So it may be possible to actually develop a profile of a person from the elemental content of their hair.
Anne Delaney: And would it be possible to actually identify say when somebody was exposed to a contaminant, a pollutant?
Bill Skinner: The theory is yes because as hair gets longer with time whatever was in the blood can be deposited in the growing hair. One particular aspect of what we call a temporal record of ingestion maybe the detection of drugs for instance. The forensic centre here in South Australia’s quite interested in the ability to detect narcotics for instance in hair and be able to tell the difference between a habitual user and a one time user.
Anne Delaney: A team at IWRI have also used time of flight secondary ion mass spectrometry to analyse glass. The research proved useful in a recent West Australian case.
Bill Skinner: We were approached by the forensic centre here in South Australia to have a look at some glass particles that were found in the glove compartment of a murder suspect and the glass particles that were found in the suspect’s pockets. Now very fine fragments of glass are used in certain types of ammunition - it’s what’s called a frictionator, and a frictionator helps to progress the thermal expansion within a cartridge and it’s very unique to gun shot residue. It gets contaminated with all the components that are in the ammunition charge and also from metals and elements from the bullet. So we looked at these two glass particles with time of flight SIMS in parallel with scanning electro-microscopy, which is the conventional method of looking at the particles, and we were able to make some determination as to the similarity between the particles. And this is in the absence of the cartridge or bullet. Basically the story went that perhaps the suspect took the cartridges, put them in the glove compartment after having had them in his pocket and then disposed of them. So we were able to say that these particles are consistent with coming from ammunition and they were found both on his person and in his glove compartment.
Anne Delaney: So what specifically did you find?
Bill Skinner: Oh we found that the type of glass was consistent. Various suppliers of ammunition use glass particles of different compositions and ostensibly the indicator element we were looking at was boron. Now boron is an element which is not easily detected by a scanning electron microscope. One, it’s present in very low amounts and secondly the technique that’s used with SEM is not particularly sensitive to boron. So with the time of flight SIMS instrument we were able to detect boron and look at similarities calibrated against standard materials.
Anne Delaney: How precise is the match that you can make with TOF SIMS though - similar is quite different to being a precise match isn’t it Bill?
Bill Skinner: Well what you can do is you can come very close within the error of the technique and as I said there was plenty of other analysis done in the case so the time of flight SIMS just added another level of certainty to the outcome.
Anne Delaney: Is that something we really have to bear in mind that these technologies and these particular techniques really just give us an extra level of evidence - they shouldn’t be relied on solely by themselves?
Bill Skinner: Oh absolutely. In general it’s very, very dangerous to rely on one technique alone. One should use as many as you have available, and in general one should use more than one technique that has a completely different mechanism of analysis.
Anne Delaney: Dr Bill Skinner from the Ian Wark Research Institute in Adelaide. One of the men at the forensic coal face here in Australia is Dr. Chris Leonard, Manager of Forensic Operations Support for the Australian Federal Police. He also maintains high tech forensics are best used as an adjunct to other forensic methods, not as a replacement for conventional technologies, or good solid police work. One technology that the AFP has recently got their hands on is isotope ratio mass spectrometry.
Chris Leonard: With the isotope ratio system all materials have a particular abundance of the different isotopes that exist and we can analyse the ratio of particular isotopes and it’s been determined that those ratios vary significantly between different sources of the same material. Now as an example we are using our instrument to analyse explosives and we have analysed an explosive known as PETN from different sources, in this case from different manufacturers, and the instrument can not only tell us that we are analysing a sample of PETN but actually indicate that it is from a particular manufacturer.
Anne Delaney: So this would be useful after a bomb explosion for instance?
Chris Leonard: Correct and once we’ve gone through the validation of this new technique then we could apply it in case work to assist us with, for example, a bombing investigation to not only link a particular explosive to a particular manufacturer but perhaps also to a particular batch of explosive from that manufacturer and then through purchasing records determine where that explosive has been purchased.
Anne Delaney: And clearly the imperative to get that information faster these days is I would presume, not only to catch the culprits but possibly to prevent further bombings?
Chris Leonard: Yep, that’s correct and the faster we can get a result to an investigator then the better the investigator can direct their investigations which as you suggest can lead to the arrest of the individuals which will obviously slow down their activities and possibly prevent another incident occurring.
Anne Delaney: If you’d had the isotope ratio system at the time that you were investigating the Bali bombing how would that have assisted?
Chris Leonard: Such an analysis could have assisted us in making comparisons with samples of materials that had been found at different premises so it would give us what we call better evidential value in terms of its value in a court setting to actually prove that an individual, or indicate that an individual has been involved in the incident. So it would give us in the end stronger evidence.
Anne Delaney: And so is this something that you can actually use in the field?
Chris Leonard: This particular instrument at this point in time, the isotope ratio mass spectrometer, is a laboratory based system. However, there’s a general push within the instrument manufacturers to increasingly miniaturise their equipment which for us brings with it the possibility of taking these items of equipment into the field to do more on site analysis, cause it’s feasible that within five to ten years it would be a field portable piece of equipment.
Anne Delaney: And is that where Australian forensics is really heading in trying to make it lighter, more portable and faster?
Chris Leonard: Yes, I think it’s a general trend worldwide that we are looking more and more towards field portable equipment to do better screening of samples in the field for a number of reasons. Firstly it gives us an initial result that can be immediately provided to the investigator to help the investigation. It can also better screen these samples so that the number of samples we need to take back to our main laboratory for full analysis is reduced. So rather than inundating a laboratory with a large number of samples that may not actually be relevant we would only take back to the laboratory the samples where we need confirmation of the field based test.
Anne Delaney: So in that case, if there is this heading towards lighter, more portable and faster, what role do you think equipment and new cutting edge machinery like a synchrotron and time of flight secondary ion mass spectrometry, what role will that machinery play in the future?
Chris Leonard: I think the type of machinery you’re talking about, the machinery that will probably remain laboratory based. That will still be a necessity in that while we may be able to do a lot more testing in the field that does not replace the full laboratory analysis that is required at the end of the process. We still require that final confirmation before the evidence that would go to court. We’re simply looking at getting the field based results to give us an initial indication and to help the investigation rather than being the final evidence that goes to court.
Anne Delaney: In terms of the future of forensics where do you think we need to be concentrating our efforts now in Australia?
Chris Leonard: I think looking into the future, I see more and more of our traditional lab based instruments being miniaturised to the point that we can at least do part of that testing in the field. And one area where we are particularly interested is using technologies such as ‘lab on a chip’ where you can essentially reduce the size of a full laboratory system down to literally a silicone chip. Our hope is that within the next five to ten years that will generate, for example, field portable DNA profiling kits so we can do screening of biological material at crime scenes using these DNA profiling kits. Again, so that we have very early information for the investigation but again also to cut down on the number of samples that have to go back for full laboratory testing.
Anne Delaney: So with something like that you could actually determine for instance how many bodies were at a disaster scene very quickly?
Chris Leonard: Absolutely, it would be very useful with the disaster victim identification. For example the work that had to be done up in Bali to identify the victims from that incident but if we had had on site DNA profiling that would have made the process much faster. Probably where we’re at the moment with miniaturisation is more micro-technology. That will have an impact over the next five to ten years and then we’ll see nano-technology further on.
Anne Delaney: Dr Chris Leonard from the Australian Federal Police. Which is where we’ll have to leave our trench coats, TOF SIMS, sleuthing and synchrotrons. Production on The Buzz this week from Sue Clark and John Diamond. I’m Anne Delaney and I’ll be back next Saturday morning. Till then have a great week.
Guests on this program
Professor Akito Kakizaki
Synchrotron Radiation Laboratory,
University of Tokyo
Dr Chris Leonard
Manager of Forensic Operations Support,
Australian Federal Police
Dr Bill Skinner
Senior Research Fellow,
Ian Wark Research Institute
University of Adelaide
Dr Michael Martin
Advanced Light Source,
Berkeley Lab, California
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