In 1953, British scientists Francis Crick and James Watson discovered that DNA (deoxyribonucleic acid) molecules carry inherited genetic information that enable life to sustain itself. They identified the structure of DNA as millions of atoms arranged in a double helix. Their discovery led to the understanding of the nature of inherited diseases, and ultimately to the hotly contested science of genetic engineering. In the 1980s, DNA testing was developed to help identify criminals.