The Night Hawks by Elly Griffiths

Ruth is back at the University of North Norfolk, now as the head of the archaeology department. When a group of detectorists discover some items that seem to be from the Bronze Age on a beach along with a dead body, Ruth is called to the crime scene to excavate. When an older couple are found dead of what appears to be a murder-suicide, DCI Nelson and his team wonder if the two cases are related, especially since the son of the victims, Paul Noakes, was present at the beach. Then, another death occurs and it becomes even clearer that all the deaths are connected. The Night Hawks continues the stories of Ruth and her family and friends in this long-running mystery series. It will be published in June.