Research has shown that there is no scientific basis for requiring a set number of corresponding minutiae in two prints in order to declare an identification.  Every latent print is unique in the way it was deposited on the surface, and factors such as pressure, movement, the condition of the surface itself, the amount of residue, as well as the quantitative and qualitative condition of the visible features within the latent print all play a part in identification.  The clarity of the known exemplars also affect the ability to make an identification.