Adams is a federal agent.
Season 6
Agent Adams shows up at Bobby Singer's house with Sheriff Jody Mills. He is looking for Rufus Turner, but Bobby denies knowing Rufus, and Sheriff Mills tries to distract him. Agent Adams is persistent, and he finds the spot where the Okami was buried. Fortunately, there is no longer any evidence of a crime because Rufus failed to kill the Okami, and it had escaped its own grave.[1]