Tell me if im wrong..

During the start of an episode in season four. Booth is wondering why Brennan doesnt want her father working at the Jeffisonian. Brennan says something about him being a murderer. And Cam points out that Brennan has killed someone before. In another episode Booth and Brennan were fighting over how many people Booth had killed and Brennan brought up she had only killed one person. If i recall correctly Brennan shot and killed a man as he was about to kill Booth in an episode with Eps. She also killed Pam, after she had shot booth. That makes 2 kills, yet they always only mention 1??..?