As the F.B.I. continues to conduct interviews with everyone at the Pensacola Naval Air Station who may have had contact with the gunman, identified as Second Lt. Mohammed Alshamrani, a new report emerged that the Saudi trainee filed a formal complaint earlier this year against one of his instructors, who left him “infuriated” in class by tagging him with a derogatory nickname.

The complaint, quoted in a communication circulated among people connected to the flight training, said that the instructor referred to Lieutenant Alshamrani as “Porn Stash” in front of about 10 other aviation students, embarrassing and angering him.

“I was infuriated as to why he would say that in front of the class,” the Saudi trainee wrote in his complaint, as quoted in the summary. The document was reviewed by The New York Times and authenticated by a person who spoke with Lieutenant Alshamrani shortly after the incident.