DO NOT PROCEED IF YOU HAVEN'T WATCHED "THE WALKING DEAD" SEASON 6 FINALE!
I'll keep this one short and sweet!
One word Gimple used to describe how fans would digest the finale has really started to pick up steam and this theory about who Negan killed is starting to pick up momentum. That one word is "Zapruder" Urban dictionary defines it as "To watch a film over and over intently to analyze it"
Scott Gimple and Robert Kirkman said on the "Talking Dead" season finale that the fans would zapruder the last scene. Robert kind of alluded to the fact that there was a subliminal in that message. I along with a slew of fans on the internet believe that it was Abraham who died at the hands of Negan because the term "zapruder" was derived from "Abraham Zapruder" He was the man that filmed the infamous Kennedy assassination. Is it a coincidence that they both share the same name? You decide.
The Kennedy assassination brought hundreds of conspiracy theories about the real culprit and the motives behind it, just like the finale is doing with who Negan killed now.
The show has been doing this with a few characters, they build them up to the point where they hold emotional significance with the fans and kill them off. This episode was a great one for Abraham who was realizing there really was a future and that also leads me to believe he was the one that got killed.