Before Florida Shooting, Gunman Showed Off Videos of Mass Attacks

The Department of Defense has 5,181 foreign students from 153 countries in various training programs. Acceptance requires screening for each applicant before acceptance, including running searches for evidence of drug trafficking, support of terrorist activity, corruption or other criminal conduct.

President Trump said before flying to South Florida on Saturday evening that the government would immediately look into “the whole procedure” of accepting foreign military trainees. King Salman of Saudi Arabia, he added, “will be involved in taking care of families and loved ones” of those killed and injured in the attack.

“I think they’re going to help out the families very greatly,” Mr. Trump said.

Members of the community who gathered for Saturday’s vigil prayed for the two deputies injured while stopping the gunman, along with others injured in the gunfire.

Mike Dimick, the military pastor at Olive Baptist Church, said he had spoken with one of the injured deputies, a 21-year-old military reservist who was shot in the arm. The young man, whom he declined to name, had reminded Mr. Dimick about a conversation they had a year ago in Bible study. An 18-year-old trainee at the base had said she was frightened because she felt the location made them a target.

“He said, ‘Every time I put on my uniform and drive by the base, I think of her, and here I am, a first responder there,’” Mr. Dimick said.

The officer was doing well, Mr. Dimick said, but seemed solemn because of “the things he has seen.”

Frances Robles reported from Pensacola, Fla.; Patricia Mazzei from Miami; Eric Schmitt from Washington; and Nicholas Bogel-Burroughs from New York. Helene Cooper contributed reporting from Simi Valley, Calif., and Adam Goldman from Washington. Susan C. Beachy and Jack Begg contributed research.