The FBI said Friday the mass shooting in California was being investigated as "an act of terrorism," amid reports the female assailant had pledged allegiance to the Islamic State group online.
Here is a summary of developments in the probe:
Killer couple
Wednesday's attack was carried out by a married couple, parents of a six-month-old baby girl, with no known history of violence or radicalism.
The assailants have been identified as Syed Farook, a 28-year-old US citizen who worked for the local county in environmental matters, and Tashfeen Malik, 27, a Pakistani national.
They were killed in a shootout with police hours after the attack.
The couple had left their infant daughter with Farook's mother before the attack, according to a relative.
14 dead, 21 wounded
Fourteen people were killed and 21 wounded when Farook and Malik opened fire inside the Inland Regional Center, a social services facility in San Bernardino, California.
The attack took place inside a packed conference room rented by the county's public health department for a year-end event, which Farook had been attending.
Authorities identified the victims as six women and eight men ranging in age from 26 to 60. All but two were county employees and co-workers of Farook.
Act of terror?
The FBI said Friday the mass shooting is now being investigated as terrorism.
"We have uncovered evidence that has led us to learn of extensive planning," the assistant FBI director in charge of the Los Angeles office, David Bowdich, told reporters.
"There's a number of pieces of evidence that has essentially pushed us off the cliff to say we are now investigating this as an act of terrorism."
FBI Director James Comey said, however, that there was no indication the couple were "part of an organized larger group or part of a cell."
Authorities have also been looking into a work-related cause, following reports Farook may have snapped at his office party when a religious discussion got out of hand.
One witness said he stormed out of the event, leaving his jacket on his seat, and returned shortly after heavily armed, dressed in black tactical gear and a mask -- and accompanied by his wife.
Allegiance to Islamic State group
Malik is believed to have pledged allegiance to the Islamic State group in a Facebook post made under another name, around the time of the attack, according to media reports.
The FBI has confirmed it is looking into the supposed pledge.
"I'm aware of the Facebook posting," Bowdich told reporters. "And yes, there was a pledge of allegiance."
Pakistan, Saudi Arabia
Investigators are looking into several foreign trips made by Farook prior to July 2014, according to the FBI.
He notably visited Saudi Arabia. Federal investigators have also suggested he traveled to Pakistan, but that is denied by the family's lawyer.
His wife held a Pakistani passport and traveled to the United States on a K1 fiancee's visa.
The couple is believed to have made a pilgrimage to Mecca in the summer of 2014, during which they married. Malik has spent time living in Saudi Arabia.
Heavily armed
The couple were armed with assault rifles and handguns -- all legally purchased. They fired dozens of rounds at the Inland Regional Center, before fleeing in a black SUV.
Explosives rigged to a remote-controlled car were also found at the scene of the carnage, but the device failed to go off.
Police said 1,600 rounds of ammunition were found on the couple and in their car following the police shootout in which they died.
About 5,000 additional rounds, 12 pipe bomb-type explosive devices and bomb-making material were found at the couple's home.
AFP
Sat Dec 05 2015
In this undated handout photo released by the FBI on December 4, 2015, shows a picture of Tashfeen Malik, one of the California mass shooters. - AFP pic
Who is Prabowo Subianto, incoming president of Indonesia?
A wealthy ex-general with ties to Indonesia's popular outgoing president and its dictatorial past, looks set to be its next leader.
Iran's supreme leader says Hamas leader's death will not halt 'Axis of Resistance'
The "Axis of Resistance", built up with years of Iranian support, includes Hamas, the Lebanese Hezbollah group, the Houthi movement in Yemen, and various Shi'ite groups in Iraq and Syria.
Putin says Russia willing to seek compromises between Iran and Israel
Russia is ready to help seek compromises between arch-foes Israel and Iran, President Vladimir Putin said on Friday, saying these would be difficult but possible.
What proposals will Russia push at the BRICS summit?
The proposal is also to establish a BRICS reinsurance company to allow uninterrupted shipment of goods and key commodities between members.
Indonesia's free meals plan in the spotlight as Prabowo readies for office
Prabowo calls the programme one of the main drivers of economic growth, eventually set to add an estimated 2.5 million jobs.
Astro AWANI's revamped English news website, AWANI International, launches on Oct 21
Astro AWANI's revamped English platform delivers in-depth global news and expert analysis to keep you informed on key developments.
Israeli strikes kill 33 people in Jabalia refugee camp in Gaza, medics say
Residents of Jabalia said Israeli tanks had reached the heart of the camp after pushing through suburbs and residential districts.
Liam Payne's ex-partner calls for media restraint after 'painful' death
Cheryl Tweedy used her statement to urge the media to remember they had a seven-year-old son, Bear, who could read the reports.
Analysts: Indonesia's strong MoF leadership team to boost investor confidence
Sri Mulyani Indrawati as head of Indonesia's Ministry of Finance is expected to instil confidence among investors.
Biden offers both a carrot and a stick to Israel as his term nears an end
Israel has frequently resisted US advice and has caused political difficulties for the Biden administration.
Putin says BRICS will generate most of global economic growth
Russian President Vladimir Putin will host a summit of the group in the city of Kazan on Oct. 22-24.
ISIS Malaysia's perspective of Budget 2025
An excellent rakyat-centric budget under the overarching principle of a caring and humane economy.
Budget 2025: Record increase in STR, SARA aid initiatives
The government will provide a significant boost to the Sumbangan Tunai Rahmah (STR) and Sumbangan Asas Rahmah (SARA) initiatives next year.
Budget 2025: EPF contributions to be made mandatory for foreign workers – PM Anwar
The government plans to make it compulsory for all non-citizen workers to contribute to the Employees Provident Fund (EPF).
What policies to expect from Indonesia's new President Prabowo
Prabowo will be open to foreign investment, his aide has said, such as by offering investors management of airports and sea ports.
Budget 2025: Govt allocates RM470 mil to empower women's participation in PMKS
The Women's Leadership Apprenticeship Program will be intensified as an effort to produce more female corporate personalities.
Israel sends more troops into north Gaza, deepens raid
Residents of Jabalia in northern Gaza said Israeli tanks had reached the heart of the camp, using heavy air and ground fire.
Indonesia ramps up security ahead of Prabowo's inauguration
Prabowo Subianto will be sworn in as Indonesia's president on Sunday with Vice President-elect, Gibran Rakabuming Raka, also taking office.
Immediate allocation of RM150 mil for local authorities, DID to tackle flash floods
Datuk Seri Anwar Ibrahim said this allocation is intended to address the recent flash floods that hit the capital and several major towns.
Budget 2025: Sabah, Sarawak to continue receiving among highest allocations - PM
Sabah and Sarawak continues to be prioritised under Budget 2025, with allocations of RM6.7 billion and RM5.9 billion respectively.