Leicester University geneticist Alec Jeffreys developed DNA fingerprinting in 1985. Scientists can use DNA fingerprints to identify individuals - just like actual fingerprints. It is especially useful for paternity testing, and for solving crimes. There is enough DNA in a small blood sample to make a DNA fingerprint. Even so, DNA fingerprinting is gradually being replaced by a new technique - DNA STR profiling - for which scientists only need a few hair roots or skin cells, or drops of saliva.