The arrest last week in Sacramento, Calif., of a person suspected to be the so-called “Golden State Killer” has triggered new concerns about the privacy risks for individuals who use genetic testing services to trace their ancestry or medical history. When California investigators last week arrested Joseph James DeAngelo, they were armed with samples of his DNA that they had collected from items he had discarded from his home. The investigators linked that to DNA samples that one of DeAngelo’s relatives had uploaded to the website of GEDMatch, a Florida-based DNA analytics firm. The investigators hit on that trail during routine matches of DNA evidence from crime scenes with DNA samples that people send to genealogical websites to find out more about their ancestry or other aspects of their genetic profiles. Police said they suspect DeAngelo committed over 50 rapes and a dozen murders across California between the mid-1970s and 1986.…