San Bernardino attackers' family 'in complete shock'
Lawyers representing the family of the two San Bernardino attackers have said relatives are "in complete shock" over the shooting.
They said the family had no idea Syed Rizwan Farook and his wife, Tashfeen Malik, were capable of such an attack.
The lawyers warned against jumping to conclusions after the FBI said earlier the attack was being investigated as an "act of terrorism".
Wednesday's mass shooting left 14 people dead and 21 injured.
Tashfeen Malik, 27, and her husband Syed Rizwan Farook, 28, died in a shootout with police after the killings in the southern Californian city, east of Los Angeles.
FBI spokesman David Bowdich told reporters that officers were trying to recover data from two mobile phones found crushed in a waste bin near the scene, a social services agency.
Lawyers David Chesley and Mohamed Abuershaid said there was no evidence that the couple had extremist views.
Syed Rizwan Farook's sister, Saira Khan, told CBS News: "I can never imagine my brother or my sister-in-law doing something like this, especially because they were happily married, they had a beautiful six-month-old daughter,"
Farook is said to have had few friends and Malik has been described by family as a "caring, soft-spoken" housewife.
Tashfeen Malik was born in Pakistan and lived for 20 years in Saudi Arabia before moving back to her native country to go to university.
She and Farook, a US national, met on Muslim dating websites, the New York Times quotes officials as saying. The new couple spent about a week in Saudi Arabia last year, before returning to the US together.
She was granted a visa allowing people to enter the US to marry American citizens. Mr Chesley said Malik was very conservative. She did not interact with male family members and wore a burka, he said.
The couple used handguns and semi-automatic weapons that had been legally purchased in the US, police say.
In response to the shooting, the New York Times ran an editorial calling for stricter gun controls on the front page of Saturday's print paper. It is the first time since 1920 that the paper has run an editorial on page one.
"It is a moral outrage and national disgrace that civilians can legally purchase weapons designed to kill people with brutal speed and efficiency," the opinion piece said.
"America's elected leaders offer prayers for gun victims and then, callously and without fear of consequence, reject the most basic restrictions on weapons of mass killing," it added.
At the scene: David Willis, BBC News, California
The bomb-making equipment and the thousands of rounds of ammunition have all been removed, and the tan-coloured townhouse which Syed Farook and Tashfeen Malik called home has now returned to normal.
On Friday, the FBI completed their search of the property on this leafy suburban street, and after confiscating notebooks and computers - and even Christmas tree lights - handed the property back to its owner.
Waiting reporters were allowed a peek behind the venetian blinds, hoping to get some degree of insight into the life of the "clean-cut young man" and his young bride and baby, who never caused problems and always paid their rent on time.
And as we piled across the threshold, we encountered not the remnants of some medieval torture chamber - or even the evidence of a fanatical terrorist cell - but all the trappings of domestic mundanity: powdered baby food in the kitchen, a cot in the upstairs bedroom, nappies, books and tapestries and several copies of the Quran.
FBI Director James Comey said earlier that the investigation was in its early stages and that the couple may have been "potentially inspired" by foreign terror groups.
However, he said there was no evidence they were part of a network.
The FBI said it was also investigating reports that Malik had posted a message on Facebook pledging allegiance to Islamic State (IS).
The militant group on Saturday hailed the attack, saying it had been carried out by "two supporters of the Islamic State".
The statement, carried by IS's al-Bayan radio, gave no indication that the group had any involvement in planning the attack at the Inland Regional Center social services agency.
Bomb equipment, weapons and thousands of rounds of ammunition were later found in the couple's home.
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Who were the victims? Diverse backgrounds of the 14 people killed
Police said between 75 and 80 people were attending a party there when the shooting began.
The identities of the victims have since been released by San Bernardino's coroner. The youngest was 26 and the oldest was 60.
San Bernardino is the deadliest mass shooting in the US since 26 people were killed at a school in Newtown, Connecticut in 2012.
A Reuters/Ipsos poll on Friday showed that 51% of Americans view Muslims living in the United States the same as any other community, while only 14.6% were generally fearful of them.