Washington, D.C.-based law firm Cooper & Kirk is pitching in on the Arizona attorney general's probe into Google's location tracking practices.

The firm first dove into the role in August, according to an outside counsel agreement from the office of the state Attorney General Mark Brnovich to Cooper & Kirk managing partner David Thompson. According to the document, Brnovich is probing whether a technology company—reported to be Google—deceived consumers by tracking and storing their location data, even after people believed they opted out of such tracking. While the letter redacts the name of the company, Google is the company facing scrutiny, according to state and national media reports.

Cooper & Kirk is working for Brnovich's office on a contingency fee. If the defendant challenges the fee arrangement, however, and Brnovich and the firm are unsuccessful in defending it, Cooper & Kirk agreed to represent Arizona at a maximum hourly billing rate of $400 an hour per partner, and $250 an hour for associates.