PORTLAND, Maine - Officials have confirmed that a tissue sample from the brain of Robert Card, the gunman responsible for a deadly shooting in Maine, has been sent to a laboratory in Massachusetts for examination. The sample will be tested for signs of injury or trauma related to Card's service in the Army Reserves, according to state officials.

The motive behind Card's rampage, which resulted in the death of 18 individuals and left 13 others injured, has raised questions about his mental state and potential military-related influences. The state's chief medical examiner hopes to determine if a brain injury sustained during Card's military service may have contributed to his erratic behavior leading up to the shootings that occurred on October 25th at a bowling alley and a bar in Lewiston.

Card's body was discovered two days after the shootings in a neighboring town, and the medical examiner previously confirmed that he died by suicide. In an effort to gain further insight into Card's mental health, tissue samples were sent to the renowned laboratory at Boston University, known for its expertise in studying brain trauma, including chronic traumatic encephalopathy (CTE), commonly associated with professional football players.

The CTE Center at Boston University has refrained from commenting on the case without the family's consent. Requests for comment from two family members made by The Associated Press have so far gone unanswered.

Concerns have been raised regarding Card's exposure to repeated explosions during his training of U.S. Military Academy cadets on firearms, anti-tank weaponry, and grenades at West Point, New York. Family members disclosed that Card had shown signs of paranoid and delusional behavior prior to being hospitalized for two weeks last summer while training with fellow reservists at West Point. During this time, Card expressed thoughts that he was being falsely accused of being a pedophile.

The severity of Card's mental state prompted his fellow soldiers to restrict his access to firearms upon his release from the hospital, with at least one reservist raising concerns about the potential for a mass shooting. Despite New York and Maine having laws that allow for the removal of weapons from individuals experiencing mental health crises, Card's guns were not taken away under these provisions.

Maine law enforcement officials had been alerted about concerns expressed by Card's fellow reservists. However, when deputies attempted to check on Card's well-being several weeks before the shootings, he did not respond to their attempts, as he did not answer the door at his Bowdoin residence.

As the investigation continues, the examination of Card's brain tissue may provide critical insights into the potential impact of his military service on his mental well-being and behavior. The results of the examination may shed light on the complex factors that contributed to this tragic incident.