So, let me introduce you a group of second year students in master in forensic science. They are helping us during the summer to constitute a dataset of prints and marks of known sources and we are asking them to do fingerprint comparison exactly as it is carried out in operations. So, during the whole summer, they will carry out hundreds of cases by annotating what is in correspondence, what is not in correspondence between marks and prints. Cedric, who is sitting here, will be the verifier, that we will use to check the Mayfield case. So, I will present you Cedric. Cedric will act as the checker on that case. He will carry out the entire comparison without knowing anything about the answer reached by Marco in first comparison and we will show you how it is done on that system. The first stage is what we call an independent analysis of the mark. So, Cedric will highlight and make judgment as to the quality, clarity of the features. Here he's showing with some colors the areas of quality and he's judging that this is an area of medium quality on the top. It's a data acquisition stage where the experts without knowing anything about potential print, he's making assessment as to how the mark was deposited, under which condition, whether it was super imposed, whether we have multiple opposition of a finger or not. We already know that in this case, it is a complex mark. It is not green, it's difficult to read, and by these two areas of quality, Cedric is showing that there is a gap in between here which may suggest that we might have two oppositions, one bottom and one top part for that latent. This is also an opportunity to add notes so that can be used as laboratory notes. So, every observations which is deemed to be important for the expert will be annotated and recorded and that will follow as lab notes all throughout. So, once decisions have been made about what are the features which can be used which area, the next stage is to annotate some key elements of the features. There is different tools to do that. One tool, which Cedric is using at the moment, is called ridge tracing. So, he will trace every ridge as they appear on the mark using this tool. That allow to very clearly identify which ridges are important, what are their path, how they are organized one compared to the other, and how they stop. Like here, we have a short ridge stopping, how they stop or where they bifurcate. So, that leads to the identification of a minutiae, which is the next tool that Cedric will apply. He will indicate on the mark the minutiae. Now, the minutiae will be overlayed on top and be directed in the axis of the ridge. Here it's a different type of minutiae. We distinguish different types. One is a clear bifurcation when the ridges are making bifurcation like a fork. A ridge ending is when the ridge simply stop in the path and a tie is because of the clarity of the mark. It's difficult to know whether it's a ridge ending or bifurcation or even it's difficult to know exactly where the minutiae lies exactly. So, Cedric can adjust his confidence on the observation he is doing at the moment. So, the analysis will go through the entire mark ridge after ridge especially in a complex case like this one to gather information from the mark and to get a feel for the complexity that the comparison will have to allow. Everything is saved and it's only when it is finished and we will pre-empt this. It's only when it is finished that he will submit the case. So, when Cedric will submit the case, the analysis is kept separately and only at that point a comparison is suggested. Here we have a print which is suggested as a comparison and will continue the comparison process. So, now Cedric is moving into the comparison phase. He has on its left, the analysis and the minutia that were laid down during the analysis process, and he has a potential candidate print on the right. The duty is to check if features that have been indicated in the analysis can they be found or not on the print. If truly it's coming from the same source, we expect to find features highlighted on the mark present on the print. So, we'll focus on one area. To start with, we call this a focal point. The focal point we're going to use initially is these two ridge ending facing each other. You can see, if you move on to mark, you have two ridge ending facing each other here. So, we will start by this positioning highlighting these two minutiae. The process always goes from the mark, to look for features potentially on the print and not the reverse. We are trying to avoid to be influenced by the features on print to find them on the mark. So, here Cedric has identified four features present on the print here. That where feature that were indicated initially on the mark. He will go on features after features or ridge after ridge. He may link them to indicate which minutiae is going with who. This is what he's doing at the moment. So, Cedric will link minutiae on the mark with potential minutiae on the print, and then move from one minutiae to the other. So, the work will not stop here with these four features. All the features available on the mark will be assessed and compare against the features available in the print. It will take some time because of the complexity of the mark, but that's the only way to judge whether there's sufficient features in agreement without significant differences for Cedric to reach a conclusion. All that process will be documented here and he can annotate and provide additional notes as to the features he has used and the conclusion reached. So, at the end of his verification, in a completely independent manner, Cedric will form an opinion as to whether or not that mark was left by the same finger as a finger at the source of the print. That will be the conclusion of the verifier, Cedric acting as a verifier in this case.
