Police have used genealogy to make an arrest in a murder case

ON APRIL 24th police in California announced the arrest of Joseph DeAngelo. Mr DeAngelo stands accused of eight counts of murder. On April 27th some intriguing details emerged of what had prompted the arrest. The starting-point was genetic material recovered from the crime scenes. Though this directly matched no DNA held in a police database, analysis of it led investigators all the way back to the 1800s, to Mr DeAngelo's great-great-great grandparents. The trail they followed allegedly links Mr...