Julianne Gunnarsen

An FBI agent introduced in Season 2, joining the Boston Field Office. She personally works with them on the cases of Tyler Brandon Mills and Rex Wolfe, and despite chastising the handling of interrogating Semo Oduwale, she spontaneously shoots and kills Alice Durand, Oduwale's accomplice. Gunnarsen is later revealed to be a mole, secretly in collusion with a group responsible for obtaining and planning to use a bioweapon, having shot Durand because she was tied to the conspiracy and made mistakes that could lead to the law tracking more activity. Once exposed and admitting a full confession, Gunnarsen's arrested.