Boston federal prosecutors brought additional fraud and money laundering charges against 16 parents allegedly involved in a nationwide college admission scheme, including three Marin County residents.

The charges were announced a day after prosecutors said 14 parents charged in the scheme, including Napa vintner Agustin Huneeus Jr., would plead guilty to fraud charges.

A Boston grand jury brought the additional charges Tuesday against the group after bringing fraud charges against them last month. They already faced charges of conspiring with Newport college admissions adviser William “Rick” Singer, who has been cooperating with federal authorities, and paying large sums to him and his foundation to alter their children’s test scores and in some cases bribing athletics coaches at top schools.

Bill McGlashan, a Mill Valley resident and former top investor at the private equity firm TPG Capital in San Francisco, and Todd and Diane Blake, of Ross in Marin County, are among the group facing additional charges.

Neither McGlashan’s nor the Blakes’ attorneys responded to emailed requests for comment.

The Blakes already stood accused of conspiring with Singer to pay a total of $250,000 to facilitate their daughter’s admission to USC as a purported volleyball recruit and falsified a profile about her athletic abilities, according to the Massachusetts U.S. Attorney’s Office.

Todd Blake also allegedly mailed a check for $50,000 to former USC senior associate athletic director Donna Heinel, who has since been fired.

McGlashan was already accused of paying bribes to get his son into USC as a recruit for the college’s storied football team, even though his son did not play football and his high school, the private Marin Academy, did not field a team.

He also allegedly paid Singer $50,000 to arrange for one of Singer’s associates proctor his son’s ACT exam and secretly correct his answers.

His lawyer stated in court papers McGlashan’s case was different than the roughly 50 other parents charged in the scheme and said his son was still in high school and had withdrawn his applications.

A Boston federal judge declined McGlashan’s request to travel internationally with his family during a court appearance last month. TPG also fired him after the charges were announced although other media reports have stated he stepped down.

The fraud charges carry a potential maximum penalty of 20 years in prison and a $250,000 fine while the money laundering charges can also carry a 20 year sentence and a fine double that.