Possible extremist link in California shooting?

This photo provided by the San Bernardino County Sheriff's Department shows ammunition and weapons carried by suspects at a shootout in San Bernardino, Calif. (AP)

SAN BERNARDINO, Calif. — As San Bernardino mourned its victims, authorities Thursday detailed a massive cache of weapons, ammunition and explosives found in the shooters’ home and contacts with suspected extremists that pointed to terrorism as a possible motive.

Syed Rizwan Farook and Tashfeen Malik, the heavily armed couple who authorities say unleashed volleys of gunfire on a holiday party, had amassed an arsenal in their Redlands home that included a dozen pipe bombs and thousands of rounds of ammunition, officials said.

“The amount of armaments that he had, the weapons and ammunition, there was obviously a mission here,” David Bowdich, assistant director in charge of the FBI office in Los Angeles, said at a news conference. “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.”

The FBI expanded its probe to a search of computer files, social media and Farook’s travel history, which included trips to Saudi Arabia and Pakistan.

Farook’s foreign travel didn’t raise the usual alarms with federal agencies because he didn’t spend several months overseas or travel to places where he could have spent time in a jihadist training camp, a senior law enforcement official familiar with the investigation said. The official spoke on condition of anonymity.

Farook traveled to Saudi Arabia in 2013 during the Hajj pilgrimage to Mecca and also visited Saudi Arabia in July 2014 for nine days to pick up Malik and bring her to the United States on a K-1 fiance visa. Neither trip lasted very long, the official said.

Malik applied for lawful permanent residency on Sept. 30, 2014, and, after a background check by the FBI and the Department of Homeland Security, received her permanent resident green card in July 2015.

A senior federal official said agents believe Farook was in contact with a small number of alleged extremists, adding that they have picked up indications that he “communicated” with at least one individual whom U.S. law enforcement officials were monitoring.

Farook’s connection to the potential terror suspect may only be tangential, the source said, but the link suggests there may be a “deeper terror matrix” behind the San Bernardino shootings.

Still, authorities and officials, including U.S. Attorney General Loretta Lynch, said it was premature to characterize the event as terrorism.

Farook and Malik fired at least 65 bullets when they stormed the office party in a conference room Wednesday morning at the Inland Regional Center. Police said 75 to 80 people were in the room when the shooting started; 12 of the 14 who died, and 18 of the 21 who were injured, were county employees.

Hours later, the couple exchanged hundreds of rounds with police on San Bernardino’s streets, launching bullets into homes and terrifying residents.

When they searched Farook and Malik’s home, police recovered a dozen pipe bombs, 2,000 9-millimeter handgun rounds, 2,500 .223-caliber assault rifle rounds and “hundreds of tools” that could have been used to make additional explosive devices, San Bernardino Police Chief Jarrod Burguan said.

The couple had 1,400 assault rifle rounds and 200 handgun rounds in their car as they fled from police, Burguan said. They fired 76 rounds at officers during the shootout, and officers shot 380 rounds in return.

Farook was born in Chicago, and had worked at the San Bernardino County Health Department as an inspector for five years. Malik was born in Pakistan, according to a federal law enforcement source who requested anonymity. The couple had a 6-month-old daughter.

As their probe widened, federal officials identified three men who “were in phone contact” with Farook and Malik in the days leading up to the shooting, a government official said. He said it was not yet clear whether those men were involved in the shooting.

Two of them, Roshan Zamir Abbassi and Nizaan Ali, told the Los Angeles Times they had been interviewed by the FBI about texts and phone calls they exchanged with Farook. Both said they had not spoken to him recently and had no knowledge of his militant activities.

Abbassi — an assistant imam at the Dal-Al-Uloom Al-Islamiyah of America mosque in San Bernardino, where Farook had regularly worshipped — told the Times he barely knew Farook. He said he told the FBI that his 36 calls with Farook all were very brief.

One federal law enforcement source said that while investigators have yet to establish a clear motive in the shooting, they are leaning toward a possible “combination of terrorism and workplace” conflict.

“We’re … 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,” said the source, who requested anonymity because the investigation is ongoing.

As expected, the shooting is already a new chapter in the ever-divisive national gun debate. President Barack Obama said it was still “too easy” for people who want to kill large numbers of people to get access to high-powered weapons in the U.S.

“We’re going to have to, I think, search ourselves as a society to make sure that we can take basic steps that would make it harder, not impossible, but harder for individuals to get access to weapons,” he said.

The San Bernardino County Sheriff-Coroner’s office released the names of the 14 slain victims, who ranged in age from 26 to 60.

Vigils were held Thursday night at a mosque, a stadium and a church in the area. Another at the University of California, Riverside was scheduled for Friday.