Any idea what kind of pepper?

I purchased this as a six pack.
5 planted in the ground, very prolific. One in a pot. If not for the last I would have thought that the first five were volunteers of some sort.

I had grown Chiltepin in the general area 3 years ago; however I live in Buffalo NY with subzero winters in an area that floods and freezes. I doubt that any rogue seeds would have survived. In addition, the fruits look different – fruits in a cluster instead of Singles.