Although we cannot do anything that would exclude protected individuals from most jobs unless we have reasonable business grounds for doing so, we can do anything we have to do to run our business efficiently, effectively, productively, and profitable, as long as we can justify our actions on valid reasonable business grounds.

Make sure if you use subjective criteria when hiring that the criteria is applied evenly to all applicants for a position and that the criteria meet the standard of business necessity.  

A good way to prevent subjectivity when hiring is to use a hiring committee to make all hiring decisions.