Chief Security Officer
This character is in charge of all policing of the ship. He/she is responsible for maintaining a safe environment for the crew and maintains and manages a brig. He/she and his/her department are authorized to use deadly force in any attempt to protect the ship from hostile forces within and from without the ship.
The CSO has an office outside the ship's brig but can move about freely on the ship and is frequently present for away missions. He/she can also appear on the bridge as mission objectives dictate.
Unlike on most ships, aboard the Patriot the Chief of Security position and the Head Tactical Officer position are two separate posts. However, the Chief of Secutiry often serves as assistant tactical officer and vice versa.
Examples from Star Trek would be Worf and Tuvok.
This is a department leadership position and is heavily featured in almost all missions with many opportunities for activity.