BOSTON — A wealthy California couple pleaded guilty to charges Wednesday morning in Boston federal court for allegedly paying more than $600,000 in bribes to get their daughters accepted into college.

Bruce and Davina Isackson, of Hillsborough, California, became the first parents in the nation's college admissions cheating scandal to plead guilty in court. A dozen additional parents, including actress Felicity Huffman, have signed plea agreements with the Justice Department but await court dates later this month before their guilty pleas are official.

Federal prosecutors say the Isacksons paid Rick Singer, the admitted mastermind of the cheating scheme, through stock transfers between 2015 and February 2019 to get their older daughter into the University of California at Los Angeles and their younger daughter into the University of Southern California.

The couple last year also inquired about engaging in the scheme for their son, prosecutors say.

The Isacksons, represented by different attorneys, were seated at separate tables in the courtroom. U.S. District Court Judge Patti Saris asked each whether they understood that their guilty pleas would mean waiving a trial by jury, the ability to appeal their sentence and other constitutional rights.

"Yes, your honor," both said when asked whether they plead guilty to the charges.

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The Isacksons, who last month said they are "profoundly sorry" for their actions, pleaded guilty to conspiracy to commit mail fraud and honest services mail fraud. Bruce Isackson, the head of Bay-area real estate firm WP Investments, also pleaded guilty to money laundering and conspiracy to defraud the U.S. for deducting the payments from their taxes as charitable contributions.

In exchange for reduced sentences and no additional criminal charges, the Isacksons have also agreed to cooperate with prosecutors to provide "substantial assistance" in the investigation or prosecution of another person who has committed a potential crime.

The couple faces a maximum penalty of 20 years in prison for the mail fraud charges, and Bruce Isackson faces an additional maximum of 20 years for money laundering and five years for tax fraud. But the prosecution has recommended the "low end" of sentencing guidelines, which prosecutors said would mean between 37 and 46 months of prison time for Bruce Isackson and between 27 and 33 months for Davina Isackson.

Their sentencing date is July 31. As the couple exited the courthouse to their car, they and their attorneys declined to comment.

The government also recommended that Bruce Isackson receive a $150,000 fine, 12 months of supervised release, and pay a restitution to the Internal Revenue Service totaling $139,509, as well as an unspecified forfeiture amount. Prosecutors have suggested similar penalties for Davina Isackson.

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Although Saris accepted the plea agreements, the judge said she's "not sure about every theory" laid out by the government as it relates to each of the counts. She seemed to question the U.S. attorney's rationale in charging the couple with the mail fraud charges, in particular, but ultimately decided there's "sufficient evidence" to accept the agreement.

Still, she said a further review of the charges could be relevant when it comes to sentencing, which she's asked the court's probation department to look at in a report.

“There’s some thorny issues here. This is not a straightforward case," Saris said, adding that the defendants' sentence "may or may not be consistent with the plea agreement.”

Assistant U.S. Attorney Leslie Wright traced the couple's participation in the scheme.

She said the Isacksons first alleged bribe payment, $250,000, was made to Singer's sham nonprofit, The Key Worldwide Foundation, in July 2016 after their older daughter was accepted into UCLA as a student-athlete. Prosecutors say a sports marketing firm controlled by UCLA's head men's soccer Jorge Salcedo, was paid $100,000 by Singer to designate her as a soccer player. She said Salcedo coordinated with staff on the women's soccer team.

Although the daughter – who has been identified as Lauren Isackson – played soccer, Wright said she lacked the skill of a "recruitable player."

The Isacksons had originally pursued a similar arrangement to get the same daughter into USC as a soccer recruit, prosecutors say. But she was diverted into the regular admissions process at USC because of a "clerical error." Prosecutors say that after this happened, former USC head women's soccer coach Ali Khosroshahin – at Singer's request – forwarded the student's fake soccer profile, transcript and test scores to Salcedo at UCLA.

Singer's nonprofit gave Khosroshahin, who last coached at USC in 2013, a check totaling $25,000 for his role, prosecutors say. Salcedo and Khosroshahin have both pleaded not guilty to racketeering charges.

Davina Isackson thanked Singer in an email the day after the daughter was admitted as a student-athlete into UCLA, according to the Justice Department.

"I know it has been a rough ride but I thank you from the bottom of my heart and soul for your persistence, creativity and commitment towards helping our (daughter)," she allegedly wrote to Singer on June 29, 2016.

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Two years later, prosecutors say that the Isacksons paid Singer's Key Worldwide Foundation an additional $250,000 in April 2018 for working to get their younger daughter admitted to USC as a rowing student even though she was not competitive in rowing.

The scheme for the younger daughter began in January 2017, according to prosecutors, when the Isacksons got approval by the ACT for her daughter to take the test with extended time and over successive days.

Prosecutors say Mark Riddell – a former private school counselor from Florida who has already pleaded guilty in the scandal – flew to Los Angeles on June 9, 2017, and corrected the daughter's answers on the ACT test. The daughter would score a 31 out of 36.

Prosecutors say Singer later sent the fraudulently obtained test score and transcript to Donna Heinel, a senior associate athletic director at USC with the message, "Another crew girl." They say Singer also directed Laura Janke, a former women's soccer assistant coach, to create a fake athletics profile for the daughter. The profile listed a number of falsified crew honors.

Riddell pleaded guilty last month to mail fraud and money laundering. Janke has agreed to plead guilty to racketeering charges and heads to court later this month. Heinel has pleaded not guilty to racketeering charges.

Prosecutors say that the Isacksons paid Singer through shares of stock that were transferred to the sham nonprofit and falsely classified as charitable gifts: 2,150 shares of Facebook with a value of $251,249 in July 2016; shares of unidentified stock valuing $101,272 in July 2017; and shares of unspecified stock valuing $249,420 in April 2018.

In all, seven out of the 50 defendants – Singer, Riddell, three college coaches and now two parents – have pleaded guilty in court in the sweeping college admission case.