From WIRED:

“The cops collected DNA from a cup he discarded. The first murder case based on forensic genealogy went to trial Tuesday. Prosecutors in Snohomish County, Washington, say they can prove beyond a reasonable doubt through nascent forensic science that William Earl Talbott II is guilty of murdering two people in 1987. And they concede they never would have found their suspect without genetic genealogy. No one knows which legal precedents about the use of such testing will last, or fade, beyond the trial.”