US Capitol attacker's family says he suffered 'repeated head trauma' from years of playing football

• Capitol attack suspect Noah Green's family says he suffered from depression and "repeated head trauma."
• This head trauma was the result of years of playing football, the family said in his defense.
• Green is a suspect in an attack where a car slammed into two Capitol police officers, killing one.

The family of Capitol attack suspect Noah Green has spoken up in his defense, saying that he suffered from depression and "repeated head trauma" from years of playing football.

Green's brother Brendan said in a statement seen by the AP that his brother had displayed a "history of troubling behavior," and that his mental health issues may have stemmed from hits to the head that he suffered while playing football.

Green, 25, spent years playing the game and was a defensive back when he attended college at Christopher Newport University in Virginia.

The attack happened last Friday when Green, allegedly rammed a car into two police officers at a barricade outside the US Capitol. Video footage showed Green emerging from the crashed car, knife in hand, charging at police officers before he was gunned down.

One officer - William "Billy" Evans, an 18-year veteran and a member of the US Capitol police department's first responders unit - was killed in the attack.

Green's brother said that he was "not a terrorist by any means" and had been studying for his master's degree in business administration. However, the family added that Green suffered from "depression and potential mental illness."

The Washington Post reported that Green had sent his brother text messages before Friday's attack, saying: "Thank you for everything that you've done. I looked up to you when I was a kid. You inspired me a lot."

The Post also reported that Green's family said they were "very shocked and upset" by the attack, and "just as taken aback as the rest of the nation from this horrific event."

According to the AP, the investigation into the Capitol attack is now focusing largely on Green's mental health to determine a motive. Officials speaking anonymously to the AP said Green had been suffering from "increasingly delusional thoughts," suicidal ideation, and paranoia.

The AP reported as well that Green had written in now-removed online posts that he thought he was being surveilled and put under a government thought-control program.

Green described himself as a follower of the "Nation of Islam" and American religious leader Louis Farrakhan.

"To be honest these past few years have been tough, and these past few months have been tougher," Green wrote in the posts, referencing the trying times he went through when he turned to his newfound faith.

"I have been tried with some of the biggest, unimaginable tests in my life. I am currently now unemployed after I left my job partly due to afflictions, but ultimately, in search of a spiritual journey."

CNN reported that Green was experiencing deep paranoia in the weeks leading up to the attack. Facebook has since removed Green's Instagram and Facebook accounts, but CNN reported he repeatedly posted that he suspected the government was using "mind control" on him, and that he was suffering several afflictions "presumably by the CIA and FBI, government agencies of the United States of America."