Police vehicles are parked outside a home in Redlands, Calif., on Thursday where two suspects believed to be responsible for the mass shooting at a San Bernardino social facility had lived. Authorities said they found several explosives and hundreds of rounds of ammunition inside the home Photo by Jim Ruymen/UPI | License Photo
SAN BERNARDINO, Calif., Dec. 3 (UPI) -- The home of Syed Rizwan Farook and Tashfeen Malik -- the couple accused of killing 14 people in a shooting rampage at a Southern California social services facility Wednesday -- apparently stored a cache of firearms and explosives that the husband and wife team may have been planning to use for a large-scale attack, federal authorities said Thursday.
The Federal Bureau of Investigation and Bureau of Alcohol, Tobacco, Firearms and Explosives have been digging into the couple's backgrounds since the pair were shot dead by police, just hours after investigators say they carried out the deadly attack at San Bernardino's Inland Regional Center -- about 60 miles east of downtown Los Angeles.
Fourteen people were killed Wednesday in the deadliest U.S. mass shooting since the Sandy Hook Elementary attack three years ago. Nearly two dozen others were wounded in what authorities say was a military-style assault plotted by a couple who potentially could have been influenced by domestic and foreign terrorist sympathizers.
During a search of the couple's home in nearby Redlands Thursday, federal authorities found a stockpile of pipe bombs and thousands of rounds of ammunition, The Washington Post reported.
However, the FBI agent in charge of the bureau's Los Angeles field office told news media Thursday that it would be "irresponsible" at this stage of the investigation to call the attack terror-related.
President Barack Obama also cautioned that calling the event a terrorist attack would be premature.
"It is possible this was terrorist-related, but we don't know. It is also possible this was workplace related," he said.
Investigators say the couple stormed the social services facility during a holiday party Wednesday morning and fired as many as 75 rounds before fleeing in a rented SUV. About four hours later, police tracked them down and shot them to death following a high-speed chase and gun battle in the middle of a San Bernardino street.
Police said they found two assault rifles, two handguns and more than 1,500 rounds of ammunition on the couple after they were killed.
At least one witness said Farook had actually attended the holiday party at the Inland center earlier in the morning before he left and returned later to begin the assault.
Farook, 28, was a Chicago-born U.S. citizen and Malik, 27, was Pakistani. One source told the Los Angeles Times Thursday that Farook made at least two trips to Saudi Arabia as well as a visit to Pakistan. Malik entered the United States with Farook in July 2014 on a K-1 "fiance visa."
An intelligence source told NBC News Thursday that Farook had been in contact with multiple persons, foreign and domestic, via social media who may be linked to terrorism.
A source told The Washington Post Thursday, though, that the Facebook contacts so far do not appear to suggest a definitive tie to terrorism.
"You're allowed to like someone's Facebook page," he said. "It's very odd. It appears they were a happy couple of the Muslim faith."
Nonetheless, police say, it appears that the couple put a great deal of planning into Wednesday's attack -- a dynamic they say indicates some sort of a long-term motive.
"Nobody just gets upset at a party, goes home and puts together that kind of elaborate scheme or plan," San Bernardino Police Chief Jarrod Burguan said.
The FBI, which has taken the lead in the investigation, is now looking through the couple's computer records, travel history and interviewing acquaintances to determine if Wednesday's attack was terror-motivated.
Among the persons interviewed have been acquaintances officials say were in direct contact with Farook leading up to the shooting rampage. One of those acquaintances shared his experience with law enforcement in a Facebook post.
"Held at gunpoint when LAPD, secret service, and FBI visited my house just a few hours ago," he wrote. "The shooter used to come to our local masjid ... We Muslims condemn all acts of terror ... We have nothing to hide and I repeat we condemn all acts of terror."
Based on the weapons found in the couple's home, investigators believe they might have been planning a large-scale, coordinated attack. It wasn't immediately clear, officials said, why they decided to launch a comparatively smaller-scale attack Wednesday.
"The amount of armaments that he had, the weapons and ammunition, there was obviously a mission here. We know that," Los Angeles FBI agent David Bowdich told the L.A. Times. "We do not know why. We don't know if this was the intended target, if there was something that triggered him to do this immediately. We just don't know."
"We don't know if it was terrorism or workplace rage," U.S. Attorney General Loretta Lynch said. "There is an investigation to determine why it happened, how did they obtain the means for this and what else might have been planned."
"We are very involved in terms of trying to see if the motive was something inspired by a terrorist organization or directed by a terrorist organization, or whether he was self-radicalized," an intelligence source told the Times.
Farook had worked for San Bernardino County for five years as a health inspector.