for perimiter control and detection, thermal imaging is great. hardware and software is already widely used.
for indentification, I don't it is useful. maybe a combination of multispectral images in UV, vis and thermal IR.
I believe UV would be even better for ID, as it shows so many details in the skin itself, but it will be hard to come by any large amount of training and testing data in high resolution. Phones theses days use near IR with an pattern emitter to reconstruct a depth matte.
but collect some images and feed them into the AI, you will need a lot for anything image based and that will be difficult. maybe raw values can see past weather, blood, and daytime changes and reveal underlying patterns... who knows.