I have been following this case and this thread but haven't posted on it before.
I just wanted to add to the Amish jacket theory a bit. Traditionally, Amish men wear beards or facial hair of some sort. I don't think they do if they aren't married though, I think unmarried can/do shave.
There are more "modern" Amish peoples and of course Mennonite, Hutterite and Quaker -all of which have similar traditions and dress. I am not sure on different variations in the area, but I am boldly assuming that if you have Amish (which I feel lives the most secluded/extreme) that you would also have one or two of the groups that embraces the modern world more.
Anyway, going to this case, I doubt that an Amish person would have donated this jacket to a good will etc. *Most* of these groups wear their clothes until they can't be worn anymore, and then will reuse them as work clothes, rags or make them into quilts etc. Very little waste, high quality items that tend to be on the more pricey side for longevity.
If they were to donate it's more likely they would donate something like that to another male in their own community and not to a charity. They do donate to charity and such, but not things they can use or reuse, traditionally speaking.
Which, IMO, means that if this was a jacket that is mostly available to the local Amish community, it is likely that it was an Amish man (or someone who they work with regularly) on the bridge wearing it.
Not to say it's impossible that anyone else would have this jacket, or that it's even an Amish jacket. But, if it is, it could be an Amish person who is pictured, the jacket may have been stolen from a work site, or it could have been a gift to someone from within the community.
Where I am located, the Mennonite and Hutterite churches are actually the ones who do the MOST prison outreach and often have homeless guests who are seeking to change their ways, they also often have home church where people who are out of jail are more than welcome. If this is DN, it wouldn't surprise me at all if he had spoken to the Amish community, looked for work, maybe did work for a few days and was given a jacket as he wasn't adequately dressed etc. We do NOT have a local Amish community that I am aware of, but many of my Mennonite friends have either married into it, or married out of it. They are also very private and unless they had proof or extreme suspicion, I don't think they would come forward and say anything bad about someone. Generally speaking, they would rather pray that the person do the right thing.
Again ALL of this is just my opinion based on my own observations in my area. I would hope that if there is an Amish community close by that LE would have looked at them the way they would anybody else.
MOO