The Saudi Embassy in Washington confirmed that Mr. Farook spent nine days in that country during the summer of 2014.
Ms. Malik entered the United States on a K-1 visa, a 90-day visa given to fiancés planning to marry Americans. The couple applied on Sept. 30, 2014, for a permanent resident green card for Ms. Malik, which requires passing criminal and national security background checks using F.B.I. and Department of Homeland Security databases, and she was granted a conditional green card in July 2015.
The suspects arrived at the Inland Regional Center at 11 a.m. on Wednesday, armed with the four guns and wearing masks. Chief Burguan said the suspects were wearing “tactical vests,” with pockets for spare magazines and other equipment.
The two handguns that were recovered were bought by Mr. Farook, and all four weapons were bought legally, Chief Burguan said. A senior federal law enforcement official said the assault rifles were bought by a third person who is not considered a suspect.
Officials said the two assault rifles were variants of the AR-15, the semiautomatic version of the military M-16 rifle; one was made by DPMS Panther Arms, and the other was a Smith & Wesson M&P model, a designation meaning military and police. The senior law enforcement official said one handgun was made by Llama, and the other by Smith & Wesson.
Witnesses to the massacre reported one, two or three gunmen, and on Wednesday, officials said they thought there were probably three. Later, the police detained a person who was fleeing on foot away from the shootout with officers.
“We did ultimately determine that he was not involved in the incident,” Chief Burguan said Thursday. “He is not a suspect.”
Investigators were confident that there were just two people who did the shooting, he said.
