I'm not sure of your exact question so I'll answer it both ways. There is no way to tell if a normal patterned corn snake is het motley or het stripe, nor is there a way to tell if a phenotypic motley is homozygous motley or is carrying one motley and one stripe gene. The motley pattern is dominant to the stripe pattern and can present in all it's glorious forms no matter if it is homozygous motley or has the stripe gene as it's partner. The only way to tell is by breeding trials.