I agree, that black bar starting just aft of the head and trailing toward the back is a good indicator,along with the hump in the snout,of a A.christyi but it also could be a Tyranocromis of some type.
Yeah, that's why I mentioned a potential hybrid. Finding pure Aristochromis in LFS are pretty tough here on the east coast. Many of them are some sort of weird Tyranno hybrid that doesn't have so large a bump on its face (and male coloration is slightly different). I've purchased 6 or so of them from two different stores a couple of years ago. I was pretty bummed to learn that they weren't right after I had been growing them out for more than a year.
A good example of the impact that a dishonest/irresponsible breeder can on the hobby. Not trying to turn this into one of "those threads." Just saying....