- Where the others killed all Torchwood or as my lil bro suspects, were UNIT?
I'm guessing Jack knows more about this than he's told Gwen and Ianto. His is the only name on the kill list, not theirs - but Agent Awful seems to be working on the assumption that he may have communicated something to them (Frobisher says "if he talks we've had it" but they haven't TOLD him anything... so he already knows).
I'm guessing Jack was involved with this back in the Sixties. Maybe against it, or went along reluctantly... but this is somewhat hinted at by a....
comment that Jack is going to be revealed to have done something "shocking" (Barrowman was worried fans might not like Jack quite as much when they find out) and that, being immortal, he has to live with his guilt a very long time.
The other names on the list typically say Retired, so I'm guessing they were government personnel/Army officers involved in the original unscheduled bus trip for Clem and the rest... they could be UNIT, but it was likely formed later in the 1960s than 1965 given the events of The Invasion (UNIT dating is notoriously all over the place, but if it WAS the 60s it was the tail-end).