It wasn't a job that Eric O'Neill set out to do. But the 27-year-old was tapped for an assignment that would bring down perhaps the most damaging spy in U.S. history — Robert Hanssen.
When he first applied to the FBI, he was too young to become a special agent. So instead he trained to be an undercover surveillance specialist. O'Neill was trained to watch, photograph and follow any target considered a threat to national security. "We would call ourselves ghosts," he said, "because you're following someone without being seen."
O'Neill was just out of college, and newly married. He was trying to finish law school at night, and his day job as an FBI "ghost" seemed exciting. Then he was mysteriously re-assigned, and got a call from his boss on a Saturday morning.
O'Neill's supervisor drove out to his home to talk with him. When his boss arrived, he wouldn't even talk to O'Neill inside the house. The two went outside and talked in the car, for security reasons.
At the time, the FBI's then director, Louis Freeh believed that Hanssen had sold reams of secrets to the Russians, including the names of American spies, causing at least two to be executed.
O'Neill had never heard of Hanssen, but he jumped at the assignment when his boss asked if he would help catch him.
Although O'Neill was not even a full-fledged special agent of the FBI, he was chosen for a few special qualities he had. "I was Catholic and that was extremely important to Hanssen," O'Neill said, "Secondly I was male. I also knew a lot about computers."
Other than those key qualities, it was no secret that O'Neill was completely unqualified to go up against Hanssen. "There were a number of people who said if anything is going to screw this case up, it's him, because he's not trained undercover, he's a surveillance operative," O'Neill said.
On his first day in FBI headquarters, he almost proved all of his critics right. O'Neill said, "I'm thinking I'm gonna go catch the super spy," O'Neill said and then, "I get lost."
The FBI's plan was both counter-intuitive and bold. If Hanssen had access to some of the FBI's secrets and was selling them to the Russians, the FBI would create a new job just for him, and give him access to almost all the FBI secrets and then watch his every move. Part of that involved O'Neill. An FBI spokesman told 20/20 O'Neill played a small role in the case, but the bureau declined to let other agents involved in the case be interviewed.
For about six weeks, O'Neill says, they worked together in room 9930 of FBI headquarters. According to O'Neill, on his very first day, Hanssen called him in to teach him his first lesson about spies, describing something he called "Hanssen's Law."
According to O'Neill, Hanssen said the spy is always "where he has access to the information that he knows he can use to do the most damage and get the most money. And he knows how to use it and get away with it."
O'Neill said, "I really felt at that minute that he was saying, if you're onto me then try and catch me because I'm better than you and all these guys at the FBI. Because I'm the great Robert Hanssen."