With few exceptions, i refer histerids to Dr. Gruber: i'm not equipped to form an opinion (without a collection, a decent illustrated key or any prior experience IDing the nearctic histerids), so it's better to wait for his comments. That being said, from what i can make of these images and Caterino's 1997 revision, the best overall fit would be S. 'ulkei', by far the most common AZ member of the genus ('instratus'being the only other one recorded from the area).

S. ulkei seems really very likely. I'll move it there until Dr. Gruber tells us otherwise.

Hister militaris group based on the protibial shape and seeming lack of setation on the pronotal hypomeron. The protibiae don't seem to be strongly bidentate as they are in Spilodiscus. Would you be able to get a better shot of a protibia?

Revision of the group can be found here.

And I am not a doctor, nor have I ever played one on TV. ;-)

not yet a new photo - but one that shows that detail somewhat

but that will be difficult with my equipment