This flew to a UV light in the backyard. Using Smith and Cave, it keys pretty well to C. californicus which is the only one that should be in NM. The interesting thing is S&C report that the elytral apices of all species are rounded. This agrees with a series I have from Los Angeles, and one from TX (and a series I collected in Tanzania). Strangely this specimen and another I got the same way in 2006 have produced elytral apices, basically dentate. If I only had one I would suspect a mutant, there are several nuclear labs in the vicinity (just kidding :) )
I'm wondering if this is some Mexican species that has moved to NM. Sorry the photos aren't any better, these mirror-finish beetles are difficult to illuminate.