A former Georgia-Pacific paper company employee who accessed computers at the company’s Port Hudson plant after being fired is now awaiting sentencing following a guilty plea in federal court.

Brian Johnson, 44, of Baton Rouge, worked as an IT specialist and systems administrator at the Port Hudson paper mill until he was fired and escorted from the facility on Feb. 14, 2014, according to the plea agreement.

Less than two weeks later, Johnson accessed the plant’s computer system from home, transmitting codes and commands to the system in an act federal prosecutors say resulted in significant damage, affecting the distributed control system and quality control system for the machinery used to produce paper towels, the plea agreement says.

The next day, FBI agents searched Johnson’s home and discovered a remote connection to the Georgia-Pacific computer system running on Johnson’s personal computer, the plea agreement says.

Computer logs discovered on the computer documented the unauthorized entry to the mill’s system, the agreement says, and matched with logs from Georgia-Pacific’s network.

Patty Prats, public affairs manager for Georgia-Pacific’s Port Hudson mill, said Johnson worked at the plant for almost 15 years before his firing and helped write the computer code for some of the plant’s paper machines.

Changes he made to the programs left workers struggling to operate the machinery at the 24-hour-a-day mill, Prats said, and hurt the plant’s “ability to get product out of the door because computer systems were down.”

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“It was some time to figure out everything that had been done,” Prats said. “We realized what had happened fairly soon and contacted law enforcement. For us to go back and fix all the systems did take some time.”

Prats said the plant is still working to tally up the total cost Johnson’s alterations to the computer system.

A federal judge will consider the value of the damage at Johnson’s sentencing hearing, scheduled for May 19, U.S. Attorney Walt Green said.

Prats declined to discuss the reason for Johnson’s firing, citing company policy.

Johnson pleaded guilty before U.S. District Judge Brian A. Jackson on Feb. 4 to a count of intentionally damaging a protected computer and now faces a maximum sentence of up to 10 years in prison and a $250,000 fine.

Follow Bryn Stole on Twitter, @BrynStole.