The soldiers, also known as the National Guard, only appear when the player meets the failure condition of having a riot active for too long (in Sandbox mode).
Their purpose is to kill prisoners and retake the prison when a riot has not been dealt with in time. They hold assault rifles and are very efficient in silencing even the most dangerous of riots.
Soldiers do not shout warnings, as armed guards do, and will not accept surrender once they have engaged a target.
Unlike Emergency units like the riot police, soldiers cannot be controlled by the player. Members of the same squad always stay together.