"a number of school coaches are scheduled to plead guilty today"
If coaches were taking bribes, it sounds like the schools WERE involved.
The "coaches" referred to here are "college coaches," meaning people parents hire to "coach" their kids on college admissions. Help them study for SATs, help them with their applications, help them write their essays and personal statements, etc.
Except in this case, the "coaches" were hiring proctors to fill in the SAT and other standardized tests for the children they were hired to help.