dressed in a photographer's vest that was stuffed
I thought he was probably wearing a fisherman's vest or a hunting vest that had a warming device, which would have accounted for the wires and general electronic look of the thing.
However, I'm pretty much convinced - for example, by the fact that he had recently moved to an apartment complex inhabited almost entirely by Asians and Middle Eastern Muslims - that he was either an Islamic dupe or an American Islamist nutcase.
Personally, I don't think he knew he was on a suicide mission. I think he believed that he was placing charges to detonate other explosives, and suddenly, somehow - he blew up. Whether this was because he was being followed and somebody took him out with a quick headshot, knowing the charges would detonate, or because the unstable materiel blew up on its own, I don't know. But I think he believed that he was going to live to kill again, which is probably the new Islamic motto.
From what I have read, some of the London bombers apparently thought they were going home after the bombing. And some of the Madrid bombers actually did go home without any problem after they had dropped off and armed their bombs.
Jayna thought it might have been a photo vest, but I'm sure other vests have loads of pockets and are similar. If it was a fisherman's vest, he could have answered Ellison that he wanted the ammonium nitrate to blow up fish. That is easier than a rod and reel.
If detonated remotely by cell phone to cell phone, it seems it would be easy to identify the phone Hinrich carried to be detonated and then find out from whom that call was received? No?
If you knew what the explosive was, and wanted to detonate it, you'd probably shoot at it, not at the guy's head, which would be a difficult target in low light conditions, although it looks like he was sitting under a lamp post. so that might not have been quite as difficult. A head shot might not detonate the bomb, because the body would or could cushion the fall for the bomb. Shooting the bomb would be a better bet. I wonder it they checked for and/or found any bullets? There were people not too far away, 30-40 yards according to reports, surely they would have heard any rifle shot, even a suppressed one.