The brain of former NFL player Phillip Adams—who police say killed a doctor, his wife, two of their grandkids, and a repairman before shooting himself—will be tested for chronic traumatic encephalopathy, the disease that has been linked to violence in some ex-athletes. WBTV reports that the York County, South Carolina, coroner got permission from Adams’ family for the procedure. Police have not released a motive for the massacre but there are reports that Dr. Robert Lesslie had treated Adams, 32, for an undisclosed medical issue. CTE is a result of chronic brain trauma—which has been found in hundreds of football players and other athletes prone to head injuries.