'CSI' Test Can Tell Age From Drop of Blood

A new blood test from the Netherlands can determine an individual's age within a range of 9 years, the Telegraph reports. The method works by looking at a genetic feature of T cells that diminishes at a constant rate over time. The test can work with a very small amount of blood, including "situations where only bloodstains are available, which covers a large proportion of crime cases," says the lead researcher. “I wouldn't be surprised if it could be used on historical blood stains that are decades or hundreds of years old.” (More CSI stories.)