Not content with clandestine

HERE is how Chris Cooper knows he is doing his job well: Someone approaches him in the grocery store, gives him that don’t-I-know-you? squint and says, “Did we go to school together?” Probably not, Cooper says, but you might know me from films. “Nooo,” is the invariable answer. “Are you sure we didn’t go to school together?”

“That’s the whole point, isn’t it?” asks the actor who, since making his American film debut in John Sayles’ “Matewan,” has starred in projects as diverse as “American Beauty,” “The Bourne Supremacy” and “Capote.” “When they don’t know who you are.”

What sounds like counterintelligence in our celebrity-obsessed culture has long been Cooper’s ethos -- before, during and after his Oscar-winning performance as the orchid thief in “Adaptation,” a role into which he disappeared so utterly a former costar told him she didn’t realize it was him until the credits rolled. And it certainly drives his most recent performance as Robert Hanssen, the traitorous FBI agent, in “Breach.”

Considered the most destructive spy in U.S. history, Hanssen, who was arrested in 2001 and later sentenced to life without parole, was a welter of contradictions -- a devout Catholic who made videotapes for friends of his wife and he having sex, an intelligence officer who publicly eschewed the bureau’s preference for kick-the-door-in agents while secretly coveting the same sort of power, a quiet, hulking man who spent more than 20 years lying to almost everyone who knew him. In a way, Cooper is an actor, playing an actor.

“So I had the scenes that were on the page and the scenes that I’m performing in my head,” Cooper says. “The things Hanssen is saying and the things that he knows, which are two completely different things. It was a challenge, but how often does an actor get a chance to do that? That’s the joy of the profession.”

It is certainly the joy of watching Cooper’s performance. “Breach,” which opens Friday, follows the final months of Hanssen’s career when agent-in-training Eric O’Neill, played by Ryan Phillippe, is installed as Hanssen’s clerk to spy on him. Written and directed by Billy Ray, probably best known for writing and directing “Shattered Glass,” another examination of a fall from grace, it is hampered, on paper anyway, by history (we know Hanssen is caught) and because it does not expose any new information (Hanssen has never explained why he did what he did). So the emphasis is totally on the relationship between the two men and the performances, especially Cooper’s.

Cooper has long been an actor’s actor. A slight man, he can project heft when he needs to and his lined and watchful face, eyes tending toward a squint, can seem naturally menacing or noble, lost or kind. “Breach” demands a bit of all that-- to be worth watching, Hanssen must be a monster, responsible for many deaths and billions of dollars’ worth of security damage, but also human. In Cooper’s hands, he is a man who after years of smug, successful spy work is only just beginning to unravel, a man so tightly wound up in his lies and contradictions that his true personality has long since worn away.

“As despicable as some of his characteristics are, I had to go there,” Cooper says. “This is a man who set up a video camera in his bedroom so his friend in the guest room would have a live feed of him having sex with his wife. So you have to find some sort of scheevy satisfaction you have had in your life ... well, you can’t,” he adds with a wry laugh, “but you have to try.”

Unlike some actors portraying real-life characters, Cooper had few physical cues to go on. “I had no voice, I had a few seconds of video from his arrest,” he says. What he did have was O’Neill, who served as an advisor on the film. “I said to Eric, ‘Give me your best impersonation of him.’ ”

But even that had its problems -- Hanssen is over 6 feet tall, with a slow, hulking gait. “I tried a shuffling walk the first day and Billy said, ‘You keep that up, we’ll have a four-hour movie. Think of something else.’ So out that went.”

Cooper talks about acting like a craftsman, intensely and with continual acknowledgment that there are tools, skills that must be learned and honed, that it isn’t a question of chemistry, or the magic of the big screen, it’s about knowing how to do what you do.

“I wish I had the words to describe it better,” he says after trying to explain how he constructs a character. “You do the research, you try to find things in your life that resonate, you try to find the building blocks of the character.” He pauses for a moment, unhappy with his own description. So what was a detail that helped him with Hanssen? Cooper thinks a moment more.

“He would speed when he was driving with friends. Recklessly sometimes. And it freaked people out, and he enjoyed that.”

Burrowing into the mind of a home-porn-making superspy might seem an unpleasant way to spend five, six months. But after years of acting, Cooper has found the boundaries between the roles he plays and his personal life -- Hanssen did not take up temporary residence in Cooper’s household. On set, however, he kept himself to himself.

“Ryan has told people I never broke character on the set,” Cooper says, “and while that’s not exactly true, we did have to find a place to be for each scene, and it was never a chummy place for actors. And if it became that, Billy,” he adds, referring to the director, “would step in and say, ‘Settle down, we have to get this done.’ ”

In the end, of course, the Cooper style of acting is not about impersonation but embodiment. “A British reporter once told me I had a very old-fashioned style of acting,” Cooper says. “I don’t know what that means. That I’m actually acting? Friends said Hanssen was a guy you just didn’t notice. He didn’t stand out. At the bureau they called him the Mortician or Dr. Death; he had no charisma. So my biggest fear was how to do that and make people care.”

Send in an invisible actor to play an invisible man? Hearing this, Cooper smiles. “Yeah,” he says, his face finally relaxing. “Yeah, you could say that.”

mary.mcnamara@latimes.com