While officers statewide searched less than 2 percent of vehicles ticketed, Jop reported searching two out of three: 119 searches out of 178 tickets. That's two-thirds of the white drivers, four out of the five Asian drivers, and all four of the black motorists.

Those numbers sound about right, said Jop, a three-year veteran of the force. ''I work nights now. It's a time of night when it's not the savoriest people out. You're going to find drugs.''

But his police chief says it just can't be so, that Officer Jop must be checking ''yes'' on the traffic tickets even when he doesn't search.

''All I can say is, he did a horrendous job of accurately documenting the searches,'' the Tewksbury police chief, John R. Mackey, said Friday after the Globe pointed out the pattern. ''We are presently contacting people who he had stopped and cited, including some of the people who he had said he did searches [on], and we have found to date that he had not searched their vehicle. But we are continuing to look at it.''

Jop did score a drug bust on one of his vehicle searches. Just after 3 a.m. on Nov. 1, he spotted 20 bags of illegal mushrooms in the back of a car he had pulled over for speeding.

''You learn what to look for as you go along,'' said Jop.