OKLAHOMA CITY, Oklahoma - The OSBI said they believe they know who put a GPS tracking device on a state representative's truck.

Representative Mark McBride found the device back in mid-January.

At the time he thought someone was following him and new details show he was right.

News On 6 requested the documents from Travis County, Texas.

It includes a subpoena for a man out of Austin, George Shipley.

OSBI investigated and the affidavit shows Shipley hired a private investigator to follow Oklahoma State Representative Mark McBride.

They put a GPS tracking device on his truck.

“I received a notice that Mr. McBride, representative McBride, believed that his reputation was being threatened based on some legislation that he was trying to pass. We initiated an investigation at that time,” said OSBI Special Agent Steve Tanner.

McBride originally said he was tipped off in December. A friend warned him to be careful.

“I’d seen a vehicle parked behind my home, watching my home. And then I crawled under my truck and low and behold there is a little black box and that really freaked me out,” said McBride.

He knew from his source that a "wind group" wanted to discredit him.

The representative was attempting to write legislation to tax wind energy companies.

“The person that's kind of my source said 'do you ever check your truck?' because it's weird because sometimes certain people know where I’m at. And I said 'no no'. I thought ok I’ll come out here and look. I'm looking around and then, what's that?" said McBride.

That little black box under his car had a paper trail.

In court documents, OSBI Special Agent Steve Tanner writes that George Shipley hired Eastridge Investigations to dig information on McBride.

He then found out Shipley's address matched the offices of the "Wind Coalition."

The Oklahoma Multicounty Grand Jury is requesting for Shipley to appear next Tuesday at 9am.

This would happen at the Attorney General's Office.