Ronald Olson, the contractor's former deputy operations manager, is the third of four executives implicated in the scheme who has been sentenced.

Former Indiana union local manager Thomas Williamson, 70, receives four years in federal prison for 2016 extortion attempt and beating of non-union contractor.

Owner of SES Construction Consulting Group and of Global Technical Solutions and two key staffers allegedly hid hundreds of thousands in wages and other compensation in false tax returns.

The company says it has received SEC subpoenas.

Leaders of Generation Now, a PAC created to funnel money to politicians that supported an energy-reform bill that saved FirstEnergy's plants, has pleaded guilty to one count of racketeering conspiracy.