The U.S. attorney’s office in Springfield has been busy the past few years investigating a variety of fraud schemes involving state grants. Thirteen people have been charged so far, six who have pleaded guilty.

Two of them have ties to President Barack Obama. One is the daughter of his controversial former pastor, the Rev. Jeremiah Wright. Another was chief of staff to Obama’s longtime friend Eric E. Whitaker when Whitaker was Illinois’ public health chief.

In all, prosecutors are alleging a total of $16 million in fraud involving state health or commerce department grants and contracts.

Here’s a brief look at each of the criminal cases that have been filed, which prosecutors built with help from the Chicago offices of the U.S. Postal Inspection Service and the Internal Revenue Service, as well as from the Illinois Secretary of State’s Office’s inspector general: