Sentinels

The Brotherhood presented a threat to Senator Kelly. To resolve this, He introduced the project: SENTINEL (during a Public Rally) to the people. The first Sentinel prototype unveiled, detected Rogue amongst the crowd and attacked her. It caused panic amongst the gathering, as it could not be controlled by Kelly's operating system, with the help of the X-Men, the Sentinel was neutralized.

Origin
Dr. Bolivar Trask was concerned with the emergence of the species 'MUTANT', that their genetic abilities, combined with their ever-increasing numbers would lead to Homo Sapiens being subjugated by them. That was the motivation that spurred him to create his "Master Mold", a servitor/controller that would command the many 'Sentinels' that Trask would create later. Unfortunately the A.I. it had been given, began to grow exponentially and Master Mold became sentient, and made sure his progeny acquired this ability also. Ironically, unbeknownst to Trask he had fathered two children who would grow up to become mutants: Tanya (and Lawrence) who had the ability of time travel and due to the instability of her power became lost in the timestream.

When Bolivar discovered that Lawrence was 'gifted' with precognition, he went to great lengths to create a device that would disguise his son's genetic ability (from his guardians) and hid it within an amulet, that he gave Lawrence, after Bolivar realized his son had predicted his wife's death. Trask had created humanity's guardian in Master Mold, but had not factored in Sentinel Logic in problem-solving, "We were created to be the Guardians of Mankind - and to guard them properly we must RULE them completely".

Master Mold commanded the existing Sentinels to capture their creator and return with him, So that he could commence the creation of a vast army of Sentinels with the intention of World domination. Trask, after witnessing Beast's interrogation under the Psycho-probe realized that it was he, who had created the threat. To right His Wrong, in a attempt to destroy Master Mold, he sacrificed himself by triggering a catastrophic explosion. The X-Men barely escaped, Bolivar was found by his son, who, from that day blamed Mutants (specifically the X-Men ) for his father's demise, and made it his project, to vastly improve on his father's design, initially converting the Mk I's then eventually creating the superior Mark II Sentinels. They could identify/determine a mutant's power from a distance due to an encyclopaedic database and advanced scanning equipment, and could conceive a plan to nullify/neutralize all mutant powers/attacks, and incapacitate any opponent.

Judge Chalmers (a close family friend) abhorred by Lawrence's extreme solution, (and privy to the family secret) decided to shock his young ward by snatching the amulet about his neck (That, to that day had hidden his presence from his servitors) No longer masked by the amulet, his former servitors, apprehended Trask and followed his last order as their leader, "Secure All Mutants in area - - and DESTROY them", Needless to say the X-Men triumphed and saved the Day. In a future confrontation with his creations, Lawrence became involved, when Quicksilver used him, to locate his sister (the Scarlet Witch) who had been abducted by the Sentinels, in their latest scheme to rid the world of Mutants. Unfortunately, He too, came to an untimely end, crushed beneath one of his creations like his father.

Even though two generations of Sentinels had failed in their objective, the technology still lived on, the US government took possession of Trask's blueprints and specs, wherein (Steven Lang and later) Sebastian Shaw set out to build a new line of Sentinels.

Power and Abilites
Sentinels' primary form of offense is their vast array of powerful energy weaponry. They are also equipped with various items for detaining people, tendrils and energy nets, freeze rays. Sentinels are able to fly. Sentinels are powerful engines of destruction (weaponry aside) and are incredibly durable, and resistant to Extreme temperatures. They also have various devices e.g. DNA and Infra Red scanners and sonic probes capable of detecting & tracking mutants.