The document added the alleged assault lasted for roughly a minute during which the victim, who was not identified, sustained two black eyes, a gash on the nose, and splattered blood on his surroundings.
Sandhya Gupta, who sat behind the victim and witnessed the shocking incident, told ABC7 News he heard “blood-curdling screams”.
“He was just very violently and very aggressively just pummeling the guy who was in the window seat who was in front of me and it was vicious. This wasn’t like a bar room, I’m going to throw a couple of punches around, I mean this was vicious,” Gupta said.
Gupta added they soon learned the victim was unable to hear or speak.
“When he was trying to communicate with us in sign language that’s when we realized he was deaf and non-verbal,” he said.
Authorities are yet to confirm if the assaulted passenger was deaf or non-verbal as the witness claimed.
Nelson was subdued and moved to the front of the plane, where he was closely monitored by the bystander who intervened. There was no further incident and the victim’s wounds were treated by a doctor onboard, stated the FBI.
According to the affidavit, no injuries could be seen on Nelson and there was no evidence he had been provoked to commit the alleged attack.
In a statement to The Independent, a United Airlines spokesperson said, “Thanks to the quick action of our crew and customers, one passenger was restrained after becoming physically aggressive toward another customer on a flight from San Francisco to Washington Dulles on Monday.
“The flight landed safely and was met by paramedics and local law enforcement.”
Nelson is charged with one count of committing assault by beating, striking and wounding – a felony in the US. He is due to appear in court on December 11.
The US Federal Aviation Authority said it will conduct its own investigation into the incident.