With one guilty plea today and another expected, the prosecution of three college buddies is ending less than two months after suspicions were raised by a $3 million payoff at the Breeders' Cup.

Glen DaSilva, a technology management consultant from New York, admitted in federal court today that he had made about $200,000 through two conspiracies: one that used bet-processing computers to alter wagers and one that duplicated other horse players' winning tickets.

The three former fraternity brothers charged in the scheme were caught, DaSilva's lawyer said, because, "These guys are amateurs. They're really not cut out for a life of crime."

Chris Harn of Newark, Del., described as the "inside man" at Autotote, which handles most of the nation's computerized horse race betting, pleaded guilty last month to fraud and money laundering conspiracies, as DaSilva did.

And Derrick Davis of Baltimore, who held the $3 million winning Pick Six tickets for the Oct. 26 Breeders' Cup, will admit to fraud conspiracy on Thursday, said his lawyer, Steven Allen.

The three men, all 29, met at Drexel University in the 1990s and were members of the Tau Kappa Epsilon fraternity.

When they were charged, racing officials tried to reassure bettors. The National Thoroughbred Racing Association hired a consulting firm headed by former New York mayor Rudolph Giuliani to review the industry's electronic wagering system.

Magistrate Judge Mark Fox allowed DaSilva to remain free on bail and scheduled sentencing for March 11. The maximum sentence is 25 years in prison, but prosecutors said they would seek a stretch of 21 to 27 months, a $4,000 fine and $200,000 in restitution.

DaSilva "will take his medicine," said his lawyer, Edward Hayes. "My client's attitude is, 'What was I thinking of?' It was a stupid thing to do."

DaSilva refused to comment.

The key to the scheme was the discovery by Harn that he could get access to Pick Four or Pick Six wagers -- in which bettors try to select the winners of four or six consecutive horse races -- after some of the races had been run.

For the prestigious Breeders' Cup at Arlington Park in Illinois, Harn went into Davis's off-track betting account after four races had been run and altered the Pick Six bet to make it appear Davis had picked all four winners. By then covering every possible winner for the last two races, he guaranteed a win. Because several long shots won that day, the jackpot was so big it immediately raised suspicions and was never paid.

DaSilva did not confess any direct knowledge of the Breeders' Cup win, but he said he and Harn used the same method on two earlier bets that netted DaSilva $108,000.