Updated: Apr 9 2021, 6:10 ET Invalid Date, PHILLIP Adams' concussions could have triggered a degenerative brain disease which led to a killing spree that left five people dead, an expert has claimed. Adams fatally shot Dr Robert Lesslie, 70, his wife, Barbara, 69, and their two young grandchildren at the couple's home in South Carolina on Wednesday. 11 11 Adams fatally shot Dr Robert Lesslie, his wife and two grandkids at the couple's home in South CarolinaCredit: AP 11 Dr Hallie Zwibel said the concussions could have led to a degenerative brain disease known as chronic traumatic encephalopathy The York County Sheriff's Office confirmed that Adams, 32, who previously played for the 49ers, killed himself in a bedroom in his parents' home following the massacre.