"I didn't realize until I was working in the police and I was told to go up to Scotland Yard and get some testing done with Dr. Josh Davis, because I was doing very well identifying people from closed-circuit television, and I didn't have a clue that I could do it until that point.

Kenny Long: "I'm quite lucky. I can see a face, and if I see it once, I will remember that face again.

Here & Now's Peter O'Dowd finds out more about people who have this skill from Kenny Long , who used to be a police officer in the New Scotland Yard Super Recogniser Unit, and Josh Davis , who studies super recognizers in the psychology department at the University of Greenwich.

Last month British authorities said they'd identified the two men behind the poisoning of Russian ex-spy Sergei Skripal and his daughter Yulia. Scotland Yard turned to a group of detectives known as "super recognizers" — people with an uncanny ability to remember a face.

"Every single time I look at a face, I get an identification, I notice someone, it's like being a rock star in your sort of own world."

"You'd be quite amazed. I've actually identified people from the back of their head from burglaries before, so it is a very strange ability, but when it comes off, you are very excited. The thing is, every single time I look at a face, I get an identification, I notice someone, it's like being a rock star in your sort of own world. So for a rock star going onstage, that's exciting for them. Put me in a room full of people and pictures, that's amazing for me.

"It can be a burden to be quite honest, because you could be walking down the high street, and someone walking towards you, they might smile, so you think, 'Ah, I know that person,' because you recognize the face, but you don't actually know them, so you can't say hello to them.

"It's involuntary. You don't really have to try. You can just be walking down the street, you'll see that face so many times, I'll recognize them years later."

On the poisoning of Skripal and his daughter, and how super recognizers would go about solving that case

KL: "So firstly, I know the guys dealing with it would have been very excited, because the whole point is, they're going to get lots of footage to view — and fast. That's a very exciting thing, because that gives us time to review the CCTV. We know we've got to look for certain people, or if not, we've got to identify people from the footage. So we'd use many different techniques, like link series identification, whereby we keep going through the footage until we notice anomalies, that same person appearing. And obviously, because we're super recognizers, we'll recognize that person, that would go to a memory, then if we see that person again in another bit of footage, we'll start building a picture, and then we can start seeing, is that the person we're looking for?"

On the importance of CCTVs as a source of evidence for super recognizers

KL: "It's estimated about 1.5 million cameras [are] now in London, and I think it's absolutely marvelous, because being on that super recognizer unit, which I was, we used to get so much CCTV [footage] come through to us, pictures of suspects, but also, we're not always looking for suspects. Sometimes we have to look for victims, we're looking for missing persons, and having all that CCTV available to you really helps solve crimes and find people."

On an example of the types of cases he cracked as a super recognizer

KL: "There was a male, who was one of Scotland Yard's most wanted, and he was believed to be out of the country at the time. So I was in London, and I'd seen a car drive past me, and I've actually noticed the suspect — I'd never met them before, but I've seen a picture of him before. So, I've gone around in the police car, pulled him over, he's given me false details, but straight away, I've realized it was him. And he'd been stopped several times by other police officers who hadn't recognized him in London's most wanted, but luckily straight away I got him in cuffs. When we took him back for fingerprinting, it confirmed it was him."

On scientists' explanation for super recognizing, and how they think human evolution probably did not play a part in the development of this ability

Josh Davis: "We think this is sort of innate. We think that super recognizers are less than 1 percent of the population. Very, very few people have this ability. We found some very small differences in the way that their brains function, and I think that's the sort of direction that the research may be going in future.

"We think it's a different function [of the brain] … People have done research on world-champion super memorizers, who perhaps can count hundreds of packs of cards or something like this, and when they tested their face recognition ability, they found that they were not very good at all. On the other hand, super recognizers seemed to have average IQ, they seemed to be average at recognizing other types of objects, recognizing sort of streams and numbers and words and things like that. So it does seem as though it's a unique skill that is specific to faces.

"As you could imagine, in sort of prehistory, people lived in very, very small communities. Needing to know a large number of faces wouldn't have been very necessary, so that's a sort of strange situation as far as the science is concerned.

"It may be that what's happened is, the part of the brain associated with other aspects of object recognition has somehow changed slightly in these super recognizers to become very, very good at face recognition. But that's a hypothesis. That's not the science definitely."

On how computers and humans compare to each other in their abilities to recognize faces

JD: "With very, very good high-quality images, computers are operating at about the same level as an average human being. Super recognizers are still better than the best computers in the world. But with low-quality images, which most CCTV footage is, human beings still beat computers. I think in the future, what the situation is going to be, it's the best algorithms working with the best humans, the super recognizers, to make the most accurate identity decisions.

"Human beings need to sleep, unlike a computer … There must be a limit to how many images and how many people Kenny can see before he does get fatigue. So that's one limitation of humans.

"What's really impressive about Kenny's skill is his ability to rule out the huge number of faces that he knows are not of interest to him, because obviously when they're searching through CCTV footage for a suspect, for a target, most of the time, they're actually looking at faces of people they're not interested in. That is what a super recognizer can do."