Which of the following is not the basis of DNA fingerprinting?

DNA Fingerprinting is a technique to find out variations in individuals of a population at DNA level. It works on the principle of polymorphism in DNA sequences. There is a variety of different types of polymorphisms ranging from single nucleotide change to very large scale changes. SNPs  are single nucleotide polymorphisms. But because any given SNP is relatively common in the population, an analyst must examine dozens of SNPs to derive a true DNA fingerprint. For this reason, SNP analysis is rarely or not used in forensic cases.