Lyons, Grier and Snyder spoke for the first time since federal authorities announced Monday that Brandon Johnson, the school's all-time leading scorer, former coach T.J. Brown and former player Brandon Dowdy were among 10 people charged with running a sports betting business to fix games.
Grier and Snyder "continue to have our trust and our confidence," Lyons said. "It's very important for me to say that publicly."
Lyons and Snyder said it was shocking for those at the small Catholic college, which plays in the West Coast Conference, to learn of the case.
"No institution is ever immune from difficulties, and this is a lesson that we've learned this week, for sure," Lyons said.
"Other than a tragedy happening to a student-athlete, there is nothing worse that can happen in collegiate athletics than point shaving," he said. "In sports, there is nothing worse than losing the integrity of the game. It calls into question all who are involved: Was it real or was it not? ... One of our student-athletes asked this week, 'How much of my career was real?' This is the damage that point shaving inflicts. This is not a victimless crime."
Johnson finished his college career in 2010. Brown was an assistant coach at the school in the 2006-07 season, and Dowdy played at USD in the 2006-07 season before transferring to UC Riverside.
Authorities did not say how the alleged scheme worked and said they were trying to determine its scope, including the number of games allegedly involved.
The indictment alleges that Johnson, 24, took a bribe to influence a USD game in February 2010 and solicited someone else this January to affect the outcome of USD basketball games while playing for the Dakota Wizards, a development team for the NBA's Memphis Grizzlies.
Federal authorities didn't name the USD opponent in the February 2010 game, saying only that Johnson was the school's starting point guard at the time.
Johnson "was intricately involved in both the illegal gambling business and in the sports bribery schemes," U.S. Attorney Laura Duffy said at a news conference Monday.