Alex Summers, Brother. Died while resisting arrest. (See: Operation Clean-Sweep)
Gabriel Summers, Brother. In induced coma at Barton-Howell research facility.
Summers' power is to emit beams of energy from his eyes: intensely powerful, without recoil, upper limit still unknown. The power kicked in at age 14, which seems to be typical. No warning, and there were a whole lot of people nearby. He was in a cinema: a John Wayne festival in Anchorage. Seven fatalities, two of whom were Summers' mother and father.
He was incarcerated at our Buffalo holding unit for two years, then transferred to Alcatraz under the terms of the Emergency Powers Act, when the prison became a specialized, mutants-only facility. There he came to the attention of the prison governor, Harcourt Teesdale – known to the inmates as "Arcade" because of the mutant-themed amusements he would set up for guards and visitors (my report: 12/07/08).
It was Arcade who discovered that ruby quartz inhibited the propagation of Summers' energy powers. He had Summers fitted with a face mask, complete with ruby quartz lenses in the eyeholes, and he surgically removed Summers' eyelids in order to remove from him any way of shutting off his eye-beams by his own choosing. As "the Basilisk," Summers then became a bespoke form of execution for other mutant inmates at the prison.
Summers is believed to have killed Arcade in the course of his escape, but damage to the body was so extensive that it wasn't possible to determine cause of death.
I believe that Summers is motivated primarily by a desire to expiate the guilt of the deaths he's caused. His commitment to the mutant cause is unshakeable, and the threat level he represents cannot be exaggerated.
Raven Darkholme. Died in custody.
Irene Adler. Died in custody.
This was a classic case of the agency shooting itself in the foot. When Darkholme and Adler tested X-gene positive and were arrested, why did nobody think to test the girl? She was on record as an adoptive child, but we know by long experience that mutants stick to their own: there was a better than fifty percent chance that Anna-Marie would have tested positive, too, and she could have been taken into custody then, before her powers even manifested, at zero risk to our agents on the ground.
Instead, she went feral: dropped out of sight and survived somehow on the streets of various Mississippi towns before heading East. She's known to have encountered the Mutant Liberation Front in New York just before their attacks on Trask Corporation subsidiaries. We haven't been able to establish whether Legacy took any part in those attacks, but she definitely provided intel for them – obtaining site details and security codes by making casual skin-to-skin contact with employees. She absorbs memories directly by touch, and is apparently also able, in the case of mutants or other super-powered subjects, to absorb enhanced abilities in the same way.
We're missing a few links in the chain that brings her eventually into Magneto's orbit. Again, we can't link her to any of the atrocities he committed in Genosha, San Francisco or New York, but they certainly met at least once before the Fortress X barrier was raised. We're exploring the possibility that they had an intimate relationship. Testimony given under duress by subject Simon Hall (aka "Neophyte") seem to point to this.