Agent June Stahl is an antagonist in the show Sons of Anarchy during the first 3 seasons.
She is a ball busting, take-no-prisoners, foul-mouthed, manipulative, conniving Agent for the Bureau of Alcohol, Tobacco and Firearms who over-compensates for being a woman in a man's field by objectifying men.
She comes to town to investigate the club after Deputy David Hale calls. She is constantly looking for a weak link in the club, or someone closely related, to turn and give her the evidence she needs. She bends rules and doesn't worry herself about the collateral damage of her actions, of which there is plenty.
She is concerned about her career above all else and will make unusual alliances in an attempt to further it. Stahl was able to prey on Chibs Telford's desire to reunite with his family and the two worked out a deal where if Chibs delivered the True IRA to the ATF, she would rescue his estranged wife and daughter and would grant complete immunity for any crimes to SAMCRO. However, Stahl decided to change the deal (no immunity for SAMCRO) but couldn't convince Chibs to go along with it. She threatened him by saying that she herself would tell the IRA about Chibs' betrayal, but she was still unable to break him.
When Opie found out that his wife, Donna's, death was a result of Stahl making Opie appear to be a snitch, he found her and threatened her at gunpoint. However, he showed mercy and let her live. He took out the empty magazine to his gun and gave it to Stahl. After Opie left, Stahl broke down and started crying.
In the season two finale, Stahl discovers that Ethan Zobelle is an F.B.I. informant and passes the information to Chief Unser, who in turn passes it onto SAMCRO. She continued her sting operation with Edmond Hayes and was able to arrange a meeting between him and his father, Cameron. Cameron secretly told Edmond to kill Stahl, so Edmond convinced Stahl that another meeting would take place and she arranged for only herself to be present. At his home, Edmond retrieved a gun but couldn't bring himself to kill Stahl.
Stahl revealed that the ATF knew all along about Cameron's plan and that Edmond's gun was loaded with blanks. Feeling like a fool, Edmond punched Stahl and attempted to escape, but Stahl was able to fire several shots from her sidearm and accidentally killed Edmond. Soon after, Polly Zobelle showed up to say goodbye to Edmond, but instead found his dead body. Before finding Stahl, Gemma Teller appeared in the house, looking to exact revenge on Polly. Gemma killed Polly in self-defense and then discovered Edmond's body and Stahl. After telling Gemma to flee, Stahl tricked Gemma into handling her gun, making it appear that Gemma killed both Polly and Edmond