Forerunner automated turret

The automated turret is a form of equipment so far only encountered on the Halo 3 levels The Covenant, Halo and The Ark. It seems completely safe to assume that it is Forerunner technology due to the fact that it resembles a stripped-down sentinel, and fires a thin, blue, sentinel-beam-like beam at enemies. However, due to programming issues, it has major problems picking out targets and more often follows allies with its targeting system, and does not fire. But the beam is extremely powerful and can kill a full armored brute in 2 shots. Also, if the turrets are not destroyed after defeating Guilty Spark, they will attack you.