The charges stems from an incident that happened while McPherson and other officers were working on a security detail when Governor Rick Perry visited Plainview in July.
Police Chief William Mull told KAMC the Texas Rangers handled the investigation.
McPherson allegedly hit another officer in the head when the two had a disagreement.
Representatives with the Hale County District Attorney's office said McPherson has not been taken into custody as of Friday evening.
The charges of assault on a public servant, if convicted, carries 2-10 years in prison.
No disciplinary action had been taken by the Plainview PD as of Friday.
Chief Mull said McPherson took a personal vacation day Friday after learning of his indictment.
Mull did say he would visit with the town manager and HR director Monday to decide how to handle McPherson's employment status.
Several Plainview City Council member contacted by phone Friday evening said this was the first they had heard about an investigation into one of their town's highest ranking officers. According to the councilmen, none of the town's staff had briefed elected officials during the four month investigation.
Stay with EverythingLubbock.com, KAMC and KLBK as this story continues to develop.