Accused Russian spy boasted that infiltrating the US was easy. He's now in prison after getting caught with files that blew his cover.

Sergey Vladimirovich Cherkasov, pictured in Russian military uniform. Department of Justice

• Secret messages from court documents give a look into the wild life of an accused Russian spy.

• The DOJ accuses Sergey Cherkasov of operating undercover in the US, and got a cache of his messages.

• He boasted wildly about his false identity, writing "We fucking did it…