Using restriction fragment length polymorphism, the analyst produces an individualized pattern of bands, often referred to as a DNA fingerprint. The Federal Bureau of Investigation (FBI) has initiated an aggressive research program to develop this technology that includes a technical training program and efforts to establish the technology's scientific validity so that it can withstand evidentiary challenges in the courts. DNA fingerprinting will impact the investigation of murder and rape crimes. Efforts are also underway to develop a classification system that would permit the establishment of a DNA data bank, and a few jurisdictions have proposed legislation for genetic typing of sex offenders. Technology transfer efforts have included an FBI seminar, a visiting scientist program, and specialized training courses for State and local laboratories. It is anticipated that within 2 to 3 years, DNA testing will be performed routinely on evidence samples. While national implementation of DNA samples will require the commitment of additional law enforcement resources to forensic services, the costs should be offset by savings in investigative and court time. 2 figures and 2 footnotes.