The agency officers in Moscow developed a list of quirky indicators to help determine whether they were being followed. A former CIA officer, speaking on condition of anonymity because he wasn't authorized to discuss intelligence operations, recounted that the Russians tended to use cars so inconspicuous that they were conspicuous. There were always two Russians in the car in case one needed to get out on foot. At a red light, they behaved like they were parking rather than stopping at the light.
The CIA determined that certain cars with an inverted pyramid on the front grill were used by the KGB.
One former agency officer said he never took shortcuts in Moscow. He would run detection routes that could last hours. The final step involved leaving a car and riding public transportation. Then and only then, eventually moving on foot, would he secretly meet a source. Another agency officer used his wife as a decoy to distract the KGB when he left secret messages.
Sometimes the banal worked.
Persuading the Russians to stop following agency officers sometimes meant boring them. If the Russians believed it was another routine day — walking the dog, grocery shopping and taking the children to the park — they might abandon their surveillance.
To beat the Russians, they also relied on technology.
The U.S. government had cracked many of the Soviet Union's encrypted frequencies they used to conduct surveillance. An agency officer using an earpiece could sometimes determine whether chatter about making a "left" or "right" was about him and safely abort his mission.
Even with precautions, Peterson said there are things a spy doesn't know.
She had no idea the Russians had learned the identity of Trigon. They knew she was leaving something for him at a designated place at a bridge. They were waiting for her with cameras and flashbulbs when she arrived one summer's night in Moscow.