"Tacita Sed Mortiferum."
The SWAT's Biological Hazard Specialists are trained to handle worst case bio warfare situations. Terrorists planning to unleash a bio hazard attack upon unsuspecting civilians do not want to deal with these guys.
This agent is one of the possible Distinguished Agent rewards the player can receive when spending 5 stars in the Operation Broken Fang Shop within the CS:GO game client. Alternatively, this agent can be purchased from the Steam Community Market