During an arrest two years ago, Buffalo policeman Ron Clark Jr. opened an abandoned freezer on a known drug dealer's back porch and found a bulging black garbage bag. "I poked my flashlight at it," he recalls, "and it started moving. My worst fear was that it was a baby."

In fact, it was a puppy, a pit bull who would come to be known as Popsicle and—in a lovely ironic twist—would gain fame for sniffing out the kind of bad guy that nearly killed him. One year ago, Popsicle helped the feds seize 3,075 pounds of cocaine from a pineapple-laden truck at the Mexican border—the biggest drug bust ever at the Hidalgo, Texas, port of entry. "It's astounding the obstacles this dog has overcome," says U.S. Customs Service Commissioner Raymond W. Kelly.

When Officer Clark found the wounded, blood-caked animal who had apparently been used in pit-bull fights, he was undernourished, hypothermic and near death. "He was in bad shape, but I was drawn to him," says SPCA adoption counselor Shannon Wille, who named the pup Popsicle. Alas, people who visited the SPCA shelter looking to adopt a puppy were put off by his breed's reputation. They would take one look at the pit bull and walk away.

When Popsicle regained his strength, the shelter contacted U.S. Customs canine-enforcement officer Sally Barr. It was a long shot, but maybe he would qualify for the dog-training school in Front Royal, Va. Of 500 dogs Barr has tested in the last three years, only four have made the cut. "You want a dog that plays a terrific tug-of-war," says Barr. Pop-sicle did, and in February 1998 he graduated top of his class and became a celebrated alumnus two months later by detecting the record contraband cache under a tractor-trailer. "You have to imagine him," says U.S. Customs canine handler J.J. Trevino, "on his hind legs, barking, trying to reach up to the bottom of the truck."

Back in Buffalo, where the bad guy eventually got off with probation for animal cruelty, Ron Clark remains awed by Popsicle's comeback. "I still don't know why I opened that refrigerator," says Clark. "But it feels like it was meant to be."