WASHINGTON — The man who police say rammed his car into a security barrier at the U.S. Capitol on Friday and was fatally shot by police after emerging from the vehicle with a knife was a lifelong athlete who in recent months had shown growing support on social media for Louis Farrakhan and the extremist Nation of Islam group.

Noah Green, 25, was identified as the suspect in the attack that killed one U.S. Capitol Police officer and injured another, according to a law enforcement official briefed on the inquiry. Those who knew Green described him as quiet, athletic and non-violent but also told USA TODAY they were concerned about recent changes in his behavior.

Police say Green rammed a dark-colored sedan into a security barrier outside the U.S. Capitol, killing Officer William "Billy" Evans, an 18-year veteran of the U.S. Capitol Police Department. After the crash, police say, Green got out of the car with a knife in his hand, ran toward officers and ignored their commands. Officers opened fire and killed him.