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Introduction to forensic chemistry

Meet Research Fellow, Dr Alan Brailsford and hand over the pills secured at the crime scene for chemical analysis.
Hello. I’m looking for Alan. Yes, that’s me. Hello. Nice to meet you. I’m Natsumi. Hi. Nice to meet you. Nice to meet you. Would you like to hang up your coat and take a lab coat? Yeah, sure. Welcome to Forensic Chemistry. You are the Head of Chemistry? Yes, that’s right. So shall I take a look at your evidence? Yes, please. So, we’ve got evidence from the crime scene, and it’s been sent to us by a police officer, and in that we have some tablets. Yes. Yeah. So in forensic chemistry, our job is to identify those tablets. OK. We can actually do a range of different things in forensic chemistry. So today, we’re identifying tablets.
We could also be identifying drugs in people– OK. –for things like poisoning or overdose cases. Oh. We could also be looking at explosives. So, people manufacturing explosives who shouldn’t be or maybe if an explosive has been used. But for today, we’ll focus on your drugs, OK? Yes. Because we want to identify them. At the moment, we don’t know what they are. So they could be anything, right? They could be some sweets, they could be some paracetamol or they could be something like street drugs or intended for illegal activities. So our job really is to identify those, and we have to do that in a neutral manner. So we’re not expecting to find anything.
We’re just identifying them and then the evidence is the evidence. I see. Yeah? So that’s what we end up presenting to court. To do that, we can use a range of scientific equipment. So, within a forensic chemistry lab, there are lots and lots of tests we can use. Some of them, you’ve got very, very expensive pieces of equipment, so £100,000, £200,000. Some of them are quite cheap. So, we’re going to use a range of tests. The tests are divided into categories. So there can be A, B or C. A is the best, so A will give you the most accurate evidence. OK. Yeah? So, it’s something that’s quite specific that we can really rely on.
B is not quite so good and then C is not so good at all. So we want to do A test, ideally. Yes. So if we’re going to court, we want an A test. Yes. We also want another type of test, which could be a B test, and then if you get the same result from two different types of analysis, then we know we’ve got the right result, because everything agrees with each other. So, the more tests you have to agree with each other, the stronger the evidence. OK. OK. So within your terms, we’re going to do several tests. We’ll do a few A tests and a B test, and hopefully we’ll get enough evidence to go to court. Yes.
OK? So right now, we’re going to go over and see Leon, who’s going to do the TICTAC work, which is a database, and that will give us our first bit of information. OK. So would you like to lead the way? Yes. Cheers.


Last week you gained an in-depth understanding of how forensics uses DNA. Welcome to Week 3, in which you’ll find out more about the forensics lab and the importance of the chain of custody. You’ll learn how physical characteristics can provide crucial evidence, and see how chemists are able to extract information at the molecular level using chromatography and mass spectrometry.

Enjoy this chance to find out how investigators use the latest methods to gather data, and don’t forget to comment, ask questions or just tell us how you’re feeling at this stage.

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The Science Behind Forensic Science

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