This is on the Media's Midweek podcast. I'm Brooke Gladstone.

What's a sleeper spy? If you've watched the thrilling TV series called the Americans,

you know they're a rare species of spy trained from youth to burrows seamlessly in American

life and they're often Russian. And what's Bellingcat? A group of investigative journalists

specializing in using open source intelligence to solve crimes and expose criminals,

often Russian ones.

Crystal Grozev is lead Russia investigator with Bellingcat, his probe into the identities

of suspects of the 2018 poisoning in the UK of several people, most notably a Russian

double agent for British intelligence, won the European prize for investigative journalism.

Last November, he exposed another sleeper who for years posed it up to unwitting officials in NATO.

Welcome to the show, Crystal. Thanks for having me.

So last November, you were combing a list of passport numbers suspected to have been used by Russian spies.

Well, first of all, why were you doing that?

That's what I do on my spare time. And I'm not getting. When I'm on an airplane,

when I have a little time between assignments, I like to go over old datasets that we haven't

passed through completely and look for new things. So I had access to this Bellingcat

board across the database. We had kind of gone through that a few times, but I thought, well,

what else can I do with it? And one thing I decided to is look for new passports from the known

range that we had discovered earlier to belong to Russian military intelligence.

A known range of passport numbers. That is correct. We have found out in 2018 that

what the Russian GRU, the military intelligence did is for laziness or for whatever reason,

they issue passports and the fake identities in sequential numbers. So you would have one

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