An autopsy report reveals tissue samples from the brain of an Army reservist who killed 18 people during a mass shooting at a Lewiston, Maine, bowling alley and bar last October showed signs of traumatic brain injury. Robert Card was found dead of an apparent self-inflicted gunshot two days later. The 40-year-old worked at an Army hand grenade training range and is thought to have been exposed to “thousands of low-level blasts.” The findings came as a commission investigating the mass shooting is hearing testimony from several of Card’s former Army colleagues. Leading up to the shooting, Maine police had been alerted the gunman was a possible danger after he threatened to “shoot up” his military base.