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Video Transcript

Thomas Duffy, FBI Evidence Response Team Unit: Latent prints are everywhere, everything you touch, everything you handle you leave behind latent prints just like you see on TV.

What we teach them today is the basics behind latent prints. What is a latent print? And then how to best find it. Because you have to identify it, find it. You have to photograph it. You have to document it and then you have to preserve it.

We find that the students learn best by doing. You can tell them about the theory, you can show them on a powerpoint but until you actually go out there and do it, a lot of it's technique. How you hold the brush, how much powder you put on there, how you use the superglue chambers behind us to properly preserve the prints. And that actually, that small group interaction, that's where a lot of people are going to ask those questions.

How do you hold the brush? How much powder do you use? How to use the superglue chamber?

Theory is one thing, but putting it in practice–you know how far away you hold things and things like that. And this is where you get a lot of the 'oohs' and 'ahhs.' And they finally start putting together, "Okay now I know what Duffy and his instructors were talking about. I'm actually doing it. Now I know to stay away from the superglue chamber when you open it." "Okay, I put the print on there, I can see the superglue, I can see with a flashlight that it pops up."

It's almost childlike when people see that "Aha!" moment that we wait for as instructors. Now it all comes together. They come here with a certain level of expertise but we want to send them back to the field better than we got them.