New DNA Test Makes it Easier to Pinpoint Identical Twin Responsible for a Crime

DNA profiling (or genetic fingerprinting) has proved to be a revolutionary tool for forensic investigators as a means to identify potential suspects, exonerate the innocent and convict the guilty. But, like any forensic technique, it has its limitations. One limitation is in cases involving identical twins, something that has raised technical, legal and ethical problems — until now. The more closely related one human is to another, the more similar their DNA profiles. For example, the probability of a DNA match between two random, unrelated individuals is in the region of one in a billion.