SAN BERNARDINO, Calif. -- The couple who police say killed 14 people at a social-services center had built more than a dozen pipe bombs and stockpiled thousands of rounds of ammunition, officials said Thursday.
The FBI is treating Wednesday morning's mass shooting as a potential terrorist act, two law enforcement officials said Thursday. But officials emphasized that they were unsure of a motive for the attack and were not ready to declare it terrorism.
Syed Rizwan Farook, 28, and Tashfeen Malik, 27, opened fire inside the Inland Regional Center in San Bernardino, Calif., on Wednesday, killing 14 people and injuring 21 others.
The two fired 65 to 75 rifle rounds, leaving behind four spent high-capacity magazines, officials said.
Four hours later, police cornered the two in a rented SUV in Redlands, Calif., 2 miles from the center. The couple opened fire at officers, who returned fire, killing Farook and Malik.
"The suspects are believed to have fired 76 rifle rounds at the officers," said Jarrod Burguan, the San Bernardino police chief. In the shootout with 23 officers from seven agencies, he said, "law enforcement fired approximately 380 rounds at the suspects."
A San Bernardino police officer was shot in the leg, and a sheriff's deputy was cut by flying debris, Burguan said of the shootout.
Most of the carnage at the Inland Regional Center was in a single room that was filled with people Farook knew, police said. While shots rang out, other people in the building took cover in their offices, and sent frantic text messages or made panicked phone calls.
The two suspects carried two .223-caliber military-style rifles and two 9mm semi-automatic pistols. When they fled the service center, they left behind an explosive made of three pipe bombs that did not detonate, Burguan said. The three rigged-together pipe bombs had a remote-control detonating device that apparently malfunctioned, he said.
In a rented Ford Expedition with Utah plates, the couple had 1,400 rounds for the rifles and 200 for the handguns with them at the time of the shootout with police, Burguan said.
At the house where they apparently lived in Redlands, officers found more than 2,500 rounds for the assault rifles, more than 2,000 for the pistols, several hundred rounds for a .22-caliber rifle, and 12 pipe bombs. There were also supplies for making more explosives.
"Clearly they were equipped, and they could have done another attack," Burguan said at a news conference Thursday. "We intercepted them before that happened, obviously."
Law enforcement officials said the FBI had uncovered evidence that Farook was in contact over several years with extremists domestically and abroad, including at least one person in the United States who was investigated for having suspected terrorist ties in recent years, but had not been charged. The officials spoke on condition of anonymity because they were not authorized to discuss the matter publicly.
Officials called the case perplexing, saying that no clear evidence of terrorism had emerged, although the attack was clearly premeditated.
"You don't take your wife to a workplace shooting, and especially not as prepared as they were," said a senior law enforcement official briefed on the investigation. "He could have been radicalized, ready to go with some type of attack, and then had a dispute at work and decided to do something."
An overnight review of Farook's electronic devices did not provide clear answers to investigators' questions Thursday, but officials noted that the investigation was in its early phases.
"We do not yet know the motive. We cannot rule anything out at this point," said David Bowdich, the assistant FBI director in charge of the Los Angeles office. "We don't know if this was the intended target or there was something that triggered him to do this immediately."
The shooters arrived at the Inland Regional Center at 11 a.m. Wednesday. They were wearing masks and carried four firearms. Some witnesses said the couple also wore body armor, but Burguan said that appeared to be wrong. Instead, the shooters wore "tactical vests," with pockets for spare magazines and other equipment, he said.
President Barack Obama said in a statement Thursday morning that it was possible the attack was terrorism-related but also possible that it was work-related. At this stage, he said, law enforcement officials still don't know why this "terrible event occurred."
Echoing Obama, Attorney General Loretta Lynch said in Washington: "We don't know if this was workplace rage or something larger or both."
Those injured in Wednesday's shooting were taken to Loma Linda University Medical Center in Loma Linda, Calif.
Two of the wounded remained in critical condition Thursday morning, and three others were listed in fair condition, said Kerry Heinrich, the chief executive of the hospital. "All of the patients are gunshot wound victims," he said, declining to give more details.
Coroner's teams were still working at the Inland Regional Center on Thursday, and law enforcement officials said some of the bodies of victims remained there.
All four weapons in the shooting were bought legally, Burguan said. A senior federal law enforcement official said the military-style rifles were bought by a third person who is not considered a suspect in the shooting.
Officials said the two rifles were variants of the AR-15, the semi-automatic 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.
As for the two handguns, a senior law enforcement official said one was made by Llama, and the other by Smith and Wesson.
Initially Wednesday, witness accounts varied as to the number of gunmen in the massacre. The numbers ranged from one to three. Officers detained a person who was running away from the gunbattle with officers as a possible third suspect.
"We did ultimately determine that he was not involved in the incident," Burguan said Thursday. "He is not a suspect."
Investigators are now confident that two people did the shooting, he said.
Information for this article was contributed by Ian Lovett, Richard Perez-Pena, Michael S. Schmidt, Laurie Goodstein and staff members of The New York Times; and by Amanda Lee Myers, Justin Pritchard and staff members of The Associated Press.
A Section on 12/04/2015