I KEEP WAITING FOR DR. DON CATLIN TO SOUND THRILLED, or at least mildly pleased, about the mushrooming furor over the use of performance-enhancing drugs in sports. Catlin, after all, helped break the now-infamous BALCO doping scandal from this very office, a small, dark, paper-strewn space inside the UCLA Olympic Analytical Laboratory. The lab is one of the world's top facilities for analyzing biological samples from athletes to detect the use of banned substances like anabolic steroids, the blood-oxygen booster erythropoetin (EPO), and scores of other prohibited drugs that aid performance.

But Catlin—a tall, balding, 67-year-old M.D. with a handsomely craggy face—just frowns when I prod him. He sips from an old coffee mug and says the current media blitz reminds him of every other time doping has hit the news: There's a lot of noise, and yet doping persists. He thinks about this a moment and then issues a bleak verdict on the drug-policing system in which he's toiled for the past 25 years.

"People are following this old model—run 'em down, chase 'em, find 'em, assume they are guilty, drag them into testing," he says. "And athletes still get away with stuff, and I maintain you can get away with stuff with everybody looking right at you."

This realization has left Catlin profoundly frustrated. A few hours after we first meet, we sit in his lab chatting about doping politics and watching a young woman scan a computer readout from a testing machine. Suddenly, Catlin blurts out, "I don't want to do it anymore. I am 67 years old. I can walk out of this lab, turn the key, chuck it out, and say, 'That's the end. I'm going skiing.' "

Millions of dollars' worth of high-tech gear is whirring all around him. Beyond these walls there's an entire international bureaucracy devoted to catching cheaters. If Catlin is right, and all that won't stop doping, the sports world has an even bigger credibility problem than most of us realize.

And sports definitely has a problem, what with the recent congressional hearings about Major League Baseball's steroid scandal and lingering suspicions that many events—from the Olympics to the Tour de France—are tainted by cheating. In the past two years alone, U.S. anti-doping authorities have uncovered 77 violations. Most recently, homegrown cycling fans suffered a major blow when Tour stalwart Tyler Hamilton was hit with a two-year suspension after allegedly transfusing another person's blood into his body in an effort to boost endurance.

In response, sports and legislative leaders are piling on bigger punishments for doping offenders and demanding ramped-up testing. But Catlin is convinced more of the same won't help, and his voice can't be ignored: He's an insider who knows all about what science can and can't do to stop doping. He ran the drug testing for the 1984 Los Angeles Summer Olympics, the 1996 Atlanta Summer Olympics, and the 2002 Salt Lake Winter Games. These days, his lab conducts tests for the United States Anti-Doping Agency (USADA), the body that oversees drug testing for American athletes in all Olympic sports. He performs testing for the NFL, the NCAA, and minor league baseball. That's a tidal wave of tests, about 35,000 urine (and, occasionally, blood) samples per year, making his the busiest lab of its kind in the world.

Catlin also helps develop new tests, with help from the 40-some researchers and technicians in his lab—including six Ph.D.'s. In 2000 the lab figured out how to differentiate natural testosterone from an artificial drug form made from yams. Just before the Salt Lake Games, Catlin and his team came up with a way to test for darbepoetin, a long-acting form of EPO, a drug that athletes inject to increase endurance. That test was used to bust cross-country-skiing gold medalists Johann Muehlegg, of Spain, and Larissa Lazutina, of Russia.