DNA Evidence of Hess's Y Chromosome

In 1982, a US Army doctor took a blood sample from Hess. A pathologist then put some of the blood on a slide for examination under a microscope. The slide was kept at Walter Reed Army Medical Center in Washington, D.C. Eventually, they brought the slide out of storage for DNA testing. They found a living male relative of Hess who was also willing to give them a blood sample. And then they ran a test on the DNA of the Y chromosome which is inherited only through the male line.