The two attackers, Farook and Malik were found in black tactical gear and had legally purchased their two handguns.
The Pakistani-origin gunman who carried out the massacre of 14 people in California along with his Pakistani wife may have been radicalised as he was in touch with extremists, officials said today, as an arms haul from their home indicated they were planning another attack.
Police said that while searching the apartment of the couple, Syed Rizwan Farook, 28, and his wife Tashfeen Malik, 27, they found an armoury of weapons and explosives including a dozen pipe bombs and thousands of rounds of ammunition.
FBI has taken charge of the probe into Wednesday's mass shooting in San Bernardino, California, and were combing through evidence, including cell phones and a computer hard drive to determine what prompted Farook and Malik to carry out the attack that claimed 14 lives and left 21 people wounded.
The FBI is treating the shooting as a potential terrorist act, though the agency is far from concluding that it was, two law enforcement officials said.
Farook, who is Pakistani-origin, and Malik, who is a Pakistani national, fired as many as 150 bullets inside the Inland Regional Center and then in the shootout with the police that left the couple dead, officials said.
The authorities have also released the names of the 14 victims, ranging in age from 26 to 60.
With the FBI examining Farook's electronic devices, analysts and agents have found evidence that at least a day before the attacks, he began deleting data leading investigators to believe that he was planning the attack.
Farook and Malik were found in black tactical gear, sans ballistic vests, police said. The attackers had legally purchased their two handguns.
"If you look at the amount of obvious pre-planning that went in, the amount of armaments (they) had, the weapons and the ammunition, there was obviously a mission here. We know that. We do not know why," said David Bowdich, Assistant Director in-charge of the FBI's Los Angeles office.
Farook was in contact with a small number of suspected extremists, officials were quoted as saying. Not only this, he had apparently communicated with at least one person who is currently being monitored as a potential terror suspect. The communications were "soft connections" in that they were NOT frequent, an official said.
Farook, whose parents migrated from Pakistan, according to Bowdich, had recently travelled to Pakistan.
However, neither Farook nor Malik were known to the FBI or on a list of potentially radicalised people, said officials.