PERPETRATOR No. 1 was observed on the night of Aug. 3 in Anaheim, Calif., throwing certain suspicious pitches for the Minnesota Twins against the California Angels. Surrounded by the authorities and searched before 37,000 witnesses, Joe Niekro was found to have on his person an emery board suitable for performing manicures or defacing baseballs. "I file my nails before games and sometimes between innings," said Mr. Niekro. He was ejected from the game and ordered suspended for 10 days.

Perpetrator No. 2, Kevin Gross of the Phillies, was apprehended Aug. 10 in Philadelphia while pitching against the Chicago Cubs. Faced with the evidence of a piece of sandpaper affixed to his glove, he did not claim to have been pursuing a sideline in cabinet-building during idle moments on the pitcher's mound. Nevertheless, his own 10-day suspension is being appealed on the grounds that there was no evidence he had scuffed a specific baseball.

Has the great home run glut of 1987 produced the predictable response: a pitchers' crime wave? Hitting coaches and batters, who always suspect the worst of every pitcher, were on television after Mr. Niekro's ejection explaining -- with an air of authority that would do credit to the Johns Hopkins Applied Physics Laboratory -- how the cumulative air resistance generated by a barely perceptible scratch on a ball thrown with the right spin can cause it to jump suddenly to the left or right in a most disconcerting manner just as it reaches home plate.

Pitchers, meanwhile, stepped up their accusations that some hitters are "corking" their bats -- a practice by which part of the bat is drilled out and some lighter substance such as cork is secretly inserted to increase the speed of the batter's swing. Commissioner Peter Ueberroth has directed umpires to let managers have one of the opposing team's bats removed from each game if the manager requests it.

This has done little to allay the suspicion, however, which we fear is likely to continue until that time when every player must go through a foreign-substances detector each time he comes out of the dugout, and be told by an attendant: "Please empty your pockets or bat of all metal, cork, sandpaper or other illicit materials before passing through the gate. There will be a 15-minute delay in your turn at bat while the pitcher does his nails."