A sentry gun.
|Rate of fire/attack||
During gameplay, as the outbreak progresses, sentry guns will appear around areas where the military have stationed themselves. After Manhattan is quarantined by Blackwatch, all bridges leading in and out of the island will have a pair of sentry guns along with other military units stationed by. Military bases have four sentry guns at ground level and two more on the roof. When a mission is active, sentry guns can be found stationed at Red Crown Command, the Bloodtox facility, and even at specific locations during certain missions. Mercer can take out sentry guns with a Cannonball, a Flying Kick, a charged Whipfist attack, or by using weapon attacks against them.
Sentry gun turrets reappear in Prototype 2. They are stationed at restricted areas and are more of a threat than UAVs (though they are significantly less threatening than those in the first game). James Heller can take them out with a weapon, his charged Whipfist, or by throwing debris at them.