Maine mass shooter's apparent brain injury may not be behind his rampage, experts say

Boston — Brain injury experts are cautioning against drawing conclusions from newly released and limited information about evidence of a brain injury in an Army reservist who killed 18 people last year in Maine's deadliest mass shooting.

Boston University researchers who analyzed a sample of Robert Card's brain tissue said Wednesday they found evidence of traumatic brain injury. The analysis, requested by the Maine medical examiner, found degeneration in the nerve fibers allowing communication between different areas of the brain, inflammation, and small blood vessel injury, according to Dr. Ann McKee of the university's Chronic Traumatic Encephalopathy (CTE) Center.

Card had been an instructor at an Army hand grenade training range, where it is believed he was exposed to repeated low-level blasts. It is unknown if that caused Card's brain injury and what role the injury may have played in his declining mental health before he opened fire at a bowling alley and bar in Lewiston on Oct. 25.