Rain-soaked memorials for those who died in a mass shooting in Lewiston, Maine, in October 2023, the deadliest in the state’s history. AP Photo/Matt York

Brain Injury

BU CTE Center: Lewiston, Maine, Mass Shooter Had Traumatic Brain Injury

“Brain injury likely played a role” in behavioral symptoms of longtime US Army reservist who was exposed to multiple blast waves, researchers say, but he didn’t have CTE

Boston University researchers have found significant evidence that Lewiston, Maine, mass shooter Robert R. Card II had traumatic brain injuries when he killed 18 people and himself last October. The brain analysis results were released by the Concussion Legacy Foundation with the permission of Card’s family, “in an effort to prevent future tragedies.”

“While I cannot say with certainty that these pathological findings underlie Mr. Card’s behavioral changes in the last 10 months of life, based on our previous work, brain injury likely played a role in his symptoms,” said Ann McKee, director of the BU Chronic Traumatic Encephalopathy (CTE) Center, in a statement announcing the findings.

The Maine chief medical examiner’s office requested the postmortem analysis of Card’s brain by the CTE Center, which studies the degenerative brain disease CTE and other long-term consequences of repetitive brain trauma in athletes, military personnel, first responders, victims of physical violence, and others. Although best known for its work studying CTE in former football players, the center also helps host the UNITE Brain Bank, billed as the “largest tissue repository in the world focused on traumatic brain injury.” 

“I do think the case is evidence that we need to urgently understand these brain injuries, be able to detect them during life, and hopefully bring treatment to the individuals that are suffering,” said McKee in an interview with The Brink. “You want to be able to detect this early, before there are consequences.”

Card was a longtime US Army reservist who had served as an instructor at a hand grenade range, where he was exposed to thousands of blast waves over a period of years, McKee says. He reportedly had a range of concerning behavioral problems in the weeks and months leading up to his rampage.

In Card’s brain, “in the white matter, the nerve fibers that allow for communication between different areas of the brain, there was significant degeneration, axonal and myelin loss, inflammation, and small blood vessel injury,” McKee says of the structural damage the BU team observed in its analysis.

Although direct cause and effect cannot be proved, “we’ve seen similar behaviors in other individuals with these same types of injury,” McKee says, including other cases of violent acts.

“The individuals that are affected in such a way complain of symptoms. They’ve got behavioral changes, sleeplessness, agitation, difficulty thinking, slow thinking. And yet, when you do routine brain scans, nothing’s picked up. So, that’s why it’s called the invisible injury,” she says.

The CTE Center researchers did not find any evidence in Card’s brain of CTE, which they have identified in roughly 92 percent of former National Football League players they’ve studied, including former New England Patriots tight end Aaron Hernandez, who was serving a sentence for murder when he killed himself in prison in 2017.

There are differences and similarities between blast wave injuries and impact injuries like those sustained by football players, says McKee, a BU Chobanian & Avedisian School of Medicine professor of neurology and pathology, a William Fairfield Warren Distinguished Professor, and chief of neuropathology at the VA Boston Healthcare System.

“A blast injury may affect other compartments of the brain and it may not be as likely to trigger CTE,” she says. “[Card’s] injury is very similar to what we’ve seen in other blast-exposed veterans. There are many types of brain injury, and CTE is one form where there’s a buildup of tau [a protein]. We see it after other injuries, [including] blast injuries, but it’s most commonly found after impact injury.”

Neither the Card family nor the Concussion Legacy Foundation would comment further, but the family has given permission for continued research on Card’s brain, McKee says.

“Of course, our main goal is to learn how to detect this injury during life using brain scans,” she says. “We’ll be using this brain to identify what methods we could use and also looking with some of our cutting-edge research techniques like Clarity—a technique to render tissues transparent—and electron microscopy to further understand the nature of the injury.”

In the release, Card’s family said: “We want to begin by saying how deeply sorry and heartbroken we are for all the victims, survivors, and their loved ones, and to everyone in Maine and beyond who was affected and traumatized by this tragedy. We are hurting for you and with you, and it is hard to put into words how badly we wish we could undo what happened. While we cannot go back, we are releasing the findings of Robert’s brain study with the goal of supporting ongoing efforts to learn from this tragedy to ensure it never happens again.”

They also thanked the medical examiner’s office for requesting the brain analysis—and the BU team for its work. “We know it does not fully explain Robert’s actions, nor is it an excuse for the horrific suffering he caused, but we thank Dr. McKee for helping us understand his brain damage and how it may have impacted his mental health and behavior. By releasing these findings, we hope to raise awareness of traumatic brain injury among military service members, and we encourage more research and support for military service members with traumatic brain injuries. Our hearts remain with the victims, survivors, and their families.”