Rush : Season 1 Episode 3

The TRG is called out to a sports oval where a heavily-armed gunman shoots Stella, who is saved by her kevlar vest. When the gunman requests to meet with a senior officer, Lawson approaches him and finds he was actually a former weapons-master who intends on suicide-by-cop. The situation ends when, after trying to avoid shooting the man, Lawson is forced to shoot and kill the man when he pulls a handgun on him.