Restriction fragment length polymorphisms (RFLPs) associated with interspersed simple repetitive DNA arise from DNA fragment lengths that contain variable numbers of the repeated motifs. Using restriction enzymes with different 4 base pair recognition sites and the simple triplet repeat hybridization probe, (GTG)5/(CAC)5, DNA multilocus fingerprints can be obtained in man. Only the DNAs of monozygous twins show indistinguishable banding patterns. Since the bands are inherited according to Mendelian laws, DNA fingerprints can be used for identification of individuals and paternity analysis. The discriminatory power in the DNA fingerprinting technique in forensic science is demonstrated and examples of paternity testing are given.