A second person has taken responsibility for an elaborate fraud scheme at Plano ISD that netted close to $7 million in a nine-year period. Carol Ann LaRue, 68, pleaded guilty to conspiracy to commit fraud on June 24. She faces up to five years in federal prison.

LaRue and another co-conspirator worked with Kris Wilson Gentz, a manager in the security and fire systems department at Plano ISD, to generate fraudulent invoices for shell companies called Fire System Specialists and Digital Security Solutions.

From 2004 to 2013, Plano ISD paid out the invoices, which reportedly totaled around $7 million, and the three con artists split the profits.

LaRue was listed as the owner and operator of both companies. She copped to participating in the conspiracy between May 2011 and December 2013.

There is no evidence that Fire System Specialists or Digital Security Solutions ever provided any services or products to the district.

The nine-year scheme came crashing down when a Plano ISD security department employee noticed one such specious invoice. Plano ISD superintendent Richard Matkin opened an investigation into the matter and placed Gentz on leave before recommending his termination in December 2013.

"The other shoe has now dropped in the Kris Gentz-Carol LaRue fraud scheme. These defendants not only cheated the taxpayers in Plano ISD, they robbed the children," U.S. Attorney John Bales said in a statement. "This case also should serve as a warning to others who somehow believe that they can rip off the public and not be held accountable. There will always be a reckoning."

Gentz, 59, pleaded guilty to his role in the conspiracy in April. Gentz and LaRue are both awaiting sentencing.

According to Davilyn Walston with the U.S. Attorney's Office, the third co-conspirator is deceased.

Walston says the case is closed, for now. "As far as we know, no one else was involved. There's always the possibility that something else could come to light as the result of the investigation."