[MUSIC] [MUSIC] So, we'll conclude this lecture with the case of Peter Falconio and Joanne Lees. And they were a couple who were touring Australia back in 2001, and they got themselves a camper van and they were driving around Australia, and their journey took them through the very sparsely inhabited Northern Territory. And as they were driving along through the Northern Territory, they were stopped by the driver of another vehicle, and the man in the other vehicle went off, out of Joanne's sight, with Peter. She then heard a shot. From that moment, Peter Falconio has never been seen again. Joanne was captured by the man and her hands were tied together with a strap, but she was able to escape when he was distracted, and hid in a bush. He searched for her, didn't find her, and then he drove off. When she felt safe, she came up, came out of the bush, was picked up by a truck driver and taken to the nearest police station. When the police investigated, they were never able to find Peter Falconio's body. They did find one bloodstain on the road. Shortly afterwards, a suspect was arrested. And he was a drug smuggler, his business was smuggling amphetamines across Australia, and his name was Bradley Murdoch. But the question is, could he be linked to the crime scene? There were no witnesses except for Joanne Lees, so it was his word against her word. Now, on her t-shirt, there was blood. The DNA of that blood matched Bradley Murdoch, and the Australian forensic scientists calculated these tremendous odds. And when you look at these odds, you realize that blood must have been Bradley Murdoch's. But, the blood stain was on her t-shirt, it was not at the crime scene, so it only proves that Bradley Murdoch had come into contact with Joanne Lees, and it does not prove they came into contact at the crime scene. It could have been at a gas station or something hundreds of miles away. But, they were able to extract DNA from the gear stick of the camper van, and that DNA matched Bradley Murdoch. This puts Bradley Murdoch at the crime scene, because it proves he was in Peter and Joanne's camper van. And then the third piece of evidence is the strap that was used to tie Joanne Lees' hands. There was not much DNA that could be extracted from it, so they had to rely on low copy number DNA, and they were able to extract from it the DNA of Joanne Lees. It had been tied around her wrists, so obviously, it would have her DNA. They were able to extract from it the DNA of a man called Dr. Peter Thatcher. Well, who was he? Well, he was one of the forensic scientists and his DNA had contaminated the sample. And finally, they were able to extract DNA of Bradley Murdoch from the strap. But, this is low copy number DNA, so the probabilities that they calculated were a lot lower than for the bloodstain on the t-shirt. When I say a lot lower, they calculated a mere 100 million to 1, but given that the population of Australia is about 20 million, that's pretty good odds. [BLANK_AUDIO] So, what do we have? We have the blood on her t-shirt. If we did not have the DNA technology, how valuable would that evidence be? Well, without DNA technology, you could only use blood type, and if he had a rare blood type, you might have got 30 to 1 odds. What about the gear stick of that camper van? Well, without DNA technology, you wouldn't have got any evidence off that gear stick - nothing. What about the strap? Again, the only thing linking this strap to Bradley Murdoch is the DNA, so without DNA technology, there's no evidence. This is a statement made by one of the prosecutors at the trial, who said, "One of these things by itself might not have been enough. But together, there was a very damning case." So Bradley Murdoch was sentenced to 28 years, at least 28 years in prison, whereas without DNA technology, there would have been no case at all. So to sum up DNA, you've seen how we can use DNA technology to prove paternity and maternity. You've seen how DNA technology can facilitate police work, and that something as small as just nine cells can be a trace that can be individualized. And you've seen that combining DNA technology with the use of DNA databases has allowed the solving of many, many cold cases involving both the conviction of the criminals and the freeing of the innocent. [BLANK_AUDIO]