Need help identifying pepper

[Farmette]

These pictures are of a plant that is growing at my sister's home in the Hill Country of Texas. It was probably planted by the former owner and is growing in an open area underneath an exposed part of the home. We looked it up and think it might be a Chiltepine, but don't know what variety. It is VERY hot and has very small oblong fruit of about 1/4 inch, maybe a little larger, long and narrower than that. Maybe they are stunted because do not get full sun. Anway, does anyone have a guess as to what these might be. I saw on another thread that Craig did a comparison of bird peppers and I am guessing that bird pepper is a broad category that this might fit into. Would appreciate any help. Thanks! Chris