PHOTOS: Scene of mass shooting at San Bernardino social services facility
"We are now investigating this as an act of terrorism," said Dave Bowdich, assistant director, FBI Los Angeles office, during a news conference Friday. "There are no suspects currently under arrest. It is possible there may be some in the future."
Officials also announced Friday that the FBI is now in charge of this investigation.
"So far we have no indication that these killers are part of an organized larger group, there's no indication that they are part of a network," FBI Director James Comey said.
The FBI also said two phones were found smashed and tossed in a trash can. They may have been used during the attacks.
VIDEO: Look inside home of San Bernardino shooting suspects
"There are some telephonic connections between these two individuals, at least one of these individuals and other subjects of our investigation," Bowdich said.
It's believed Syed Farook's wife used an alias on social media and may have been posted something.
"I know it was in that general timeline the post was made and yes, there was a pledge of allegiance," Bowdich said.
A Facebook official says Tashfeen Malik praised the leader of the Islamic State group in a post at 11 a.m. Wednesday, when the couple were believed to have stormed a San Bernardino social service center and opened fire.
A Facebook executive confirms an account that is now deactivated displayed a message "which contained messages of praise for terrorist acts."
Investigators believe Malik came to the United States after Farook went to meet her in Saudi Arabia last year. Much of her background still remains a mystery.
During a press conference Friday, the Farook family's attorney described a very traditional Muslim family.
"And the family members knew Tashfeen as a sister-in-law. They had a basic relationship with her. It wasn't overly close, but it wasn't too distant," said Mohammad Abuershad, the Farook family lawyer. "The men did not interact with her. And the brothers did not actually ever see her face. They've never seen her face because she did wear a burka, she was totally covered."
The FBI is urging San Bernardino residents to remain vigilant and alert. They said that there is no credible threat right now in the U.S.
The Associated Press contributed to this report.
Most of the 14 people killed at a holiday banquet in San Bernardino County, California, worked in the same county public health department as the man who showed up with his wife and sprayed the hall with gunfire.
An official list of the dead was released Thursday, and families, friends and co-workers came forward to share some of their stories:
NICHOLAS THALASINOS, 52
He identified as a Messianic Jew and passionately defended Israel, actively debating about religion in online forums and in person, his friends said.
Only two weeks ago, Thalasinos, of Colton, was having a heated on-the-job discussion about the nature of Islam with Syed Rizwan Farook, his fellow restaurant inspector and one of the shooters.
Thalasinos' friend, Kuuleme Stephens, told The Associated Press that she happened to call him while he was working with Farook and that he brought her into their debate, loudly declaring that Farook "doesn't agree that Islam is not a peaceful religion."
She heard Farook counter that Americans don't understand Islam, and Thalasinos responded by saying, "I don't know how to talk with him," she said.
Thalasinos wife, Jennifer, told the AP the two "probably did have debates" but "I never got the impression it was in a bad way."
"It was more, you know, just having discussions about religion and faith," she said.
She said she believes her husband died a martyr because of his faith but he never indicated that Syed had radicalized. She said she did not believe her husband was individually targeted.
"They all got along really well. So it's shocking," she said.
YVETTE VELASCO, 27
Velasco is being described by her family as smart, motivated and full of life.
In a statement, her relatives said she was "loved by all who knew her."
"We are devastated about what happened and are still processing this nightmare," the family said.
Velasco is survived by her parents and three sisters.
"Please pray for our family and the other families who have lost a loved one as a result of this terrible tragedy," her relatives wrote.
In the aftermath of the shooting, Velasco's relatives searched everywhere for her. Mindy Velasco, her aunt, called hospitals, police and evacuee centers in a harrowing search for information, the Los Angeles Times reported.
"I'm fearing the worst," she told the paper. "She would definitely be in contact after something like this."
AURORA BANALES GODOY, 26
The wife and mother of an infant son was killed in the attack, her aunt, Rebecca Godoy, said in Facebook post that linked to Godoy's own page.
"Yesterday in the shootings in San Bernardino many families were affected. Ours was one of them," Rebecca Godoy wrote. "We will keep her flame alive so that her young son does not forget his special mother."
Godoy's cousin, Nicole Rachelle Chelley, declined further comment when contacted by the AP through Facebook email.
BENNETTA BETBADAL, 46
She was born in Iran in 1969 and came to the United States at age 18 to escape the persecution of Christians after the Iranian Revolution, according to a family statement on a fundraising account set up in her name.
Her cousin, Melani Betbadal, referred reporters to the statement and declined further comment.
She first settled in New York City but eventually moved to Rialto, California. She and her husband, a police officer, were married in 1997 and have three children ages 10, 12 and 15.
Betbadal graduated from California State Polytechnic University in Pomona with a degree in chemistry and took a job as a health inspector with San Bernardino County.
Her husband, Arlen Verdehyou, told The Daily Breeze that he and his wife exchanged texts at 8 a.m. Wednesday. He told her that he had withdrawn money from the bank and would do some Christmas shopping. Betbadal had recently decorated the family's Christmas tree.
She was planning to give a presentation at the annual holiday meeting Wednesday and was excited about it, the family said.
"It is the ultimate irony that her life would be stolen from her that day by what appears to be the same type of extremism that she fled so many years ago," the family said in the statement.
SIERRA CLAYBORN, 27
Her friends say she stood out as someone who always had an encouraging word.
Timothy J. Lee remembers meeting Clayborn in a hip-hop class at the University of California, Riverside. She was active and outgoing, praising classmates when they mastered a routine.
"She always had something encouraging to say," Lee said.
After graduating in 2010, Clayborn worked jobs in retail and at a bank before landing a position at the San Bernardino County Department of Public Health. Like a number of other victims, she inspected restaurants.
Matthew Peairs, 27, a manager at Red Baron Pizza in Big Bear Lake, California, said Clayborn visited the restaurant a day before the shooting to complete an inspection.
"She was one of the nicest health inspectors that we've ever had," he said. "She talked to us like normal people, not just doing her job."
He said they discussed their holiday plans and she mentioned she was going to the department's Christmas party Wednesday.
"She was stoked about the party," Peairs said.
Word spread Wednesday among Clayborn's friends that she was missing. FBI agents later visited her family's house to tell them that she was killed in the attack.
"It's definitely going to be different without her," Lee said.
ROBERT ADAMS, 40
The Yucaipa resident was known as a loving father and husband who married his high school sweetheart, friends said.
A fundraising page for his wife, Summer, and 20-month-old daughter, Savannah, had raised thousands of dollars in several hours Thursday.
Megan Neforos, who set up the page, said she knew Adams' wife through a Facebook group for mothers of young children.
"He was her high school sweetheart. This is tragic for her," she said. "He was an incredibly loving father and devoted husband."
LARRY DANIEL KAUFMAN, 42
He ran an independently owned coffee shop inside the Inland Regional Center where the county health workers were using a hall for their holiday banquet. The shop's workers included people with developmental disabilities, which can include epilepsy, autism and intellectual disabilities.
Eileen Richey, the executive director of the Association of Regional Center Agencies, said his death "fills us with sorrow, knowing so many families are in mourning."
Kaufman, of Rialto, was an avid participant in the Original Renaissance Pleasure Faire in Southern California each spring, said friend Katherine Panowicz, who had known him for 15 years.
She said he typically participated in parades, carrying either a pennant or a lance on a make-believe horse. The fair community is devastated to lose a friend with such a big smile, she said.
"It would change the entire environment of a room just because he had a big brilliant smile," she said.
MICHAEL RAYMOND WETZEL, 37
Friends and fellow church members appealed for help supporting his widow, Renee, a stay-at-home mom in Lake Arrowhead, California, and children.
"Michael was the most amazing person," Renee Wetzel said in a statement, issued through her friend Celia Behar. The couple had five children from previous marriages and one child together.
"He was my best friend and an incredible father who was loved by all. I have never known a better person," the statement said. "He loved his work and his family so very much. Without him, this family will never be the same. We appreciate all the love and support that everyone is showing."
Behar runs a blog for mothers where Renee Wetzel frequently posted, and she turned there to ask for prayers shortly after learning that her husband, an environmental health supervisor, could have been attacked.
"My husband was in a meeting and a shooter came in. There are multiple people dead/shot. I can't get a hold of him," she wrote.
After last month's deadly shootings in Paris, she posted a vacation photo on Facebook, overlain by the colors of the French flag.
After her husband's death was confirmed, she posted a Bible passage: "When my heart is overwhelmed lead me to the rock that is higher than I."
The Lil' Mamas blog set up an online fundraiser for the Wetzel family on Thursday and quickly raised tens of thousands of dollars.
Church of the Woods also asked its members to pray for the extended family: "Please continue to pray for Renee, his children, and his former wife Amy as they process this terrible tragedy and loss of their husband and father," the church said in a statement.
DAMIAN MEINS, 58
He was passionate about serving his community, a message he took from the priests at his Catholic high school in Riverside and carried throughout his life.
Meins never strayed far from his church or its teachings, said Walter Hackett, who met Meins some 40 years ago in high school.
"Service to others, helping others. He very much took that to heart," Hackett said.
Hackett called his friend "a good, good guy."
"Funny and smart and tall. A real quick smile, very friendly and outgoing," he said. "It's a real hard hit for all of us who knew him."
Meins married his high school sweetheart, now a Catholic school principal, and they raised two daughters, one a teacher. Meins was fondly remembered as the guy who dressed up as Santa for school pictures, according to a parent's social media posting Thursday.
Meins' Facebook page, where he can be seen smiling with his family in front of the Golden Gate Bridge in San Francisco, says he studied business administration at the University of Redlands starting in 1991. In 1979, he graduated from UC Riverside. He was also retired from the Riverside County after working there for 28 years.
In addition to working in the public health department in San Bernardino, Meins was an extended care coordinator at St. Catherine of Alexandria School in Riverside, where he also helped kids create Christmas art projects and religious murals, Hackett said.
Meins received a community award for his work in Riverside, which was based on "compassion, courage, forgiveness, generosity, humility, inclusiveness, integrity, kindness, respect and service."
A living Rosary for the Meins family was held Thursday.
SHANNON JOHNSON, 45, of Los Angeles.
Johnson was the lone victim who lived in Los Angeles, a long commute to San Bernardino County where he worked as a health inspector.
He rose before dawn every morning to get to his job from his home in Koreatown, which he shared with his girlfriend, Mandy Pfifer, who was a longtime member of LA Mayor Eric Garcetti's Crisis Reponse Team.
The mayor's office said in a statement Thursday night that "we have learned that one of our own ... is among those who lost their lives."
TIN NGUYEN, 31
She was supposed to get married in 2017, her family told media outlets.
Born in Vietnam, Nguyen was a food inspector with the county health department. She lived in Santa Ana.
ISAAC AMANIOS, 60
He was a supervising environmental health specialist.
Authorities released the names of the rest of the victims, but details about them weren't immediately available. They are:
HARRY BOWMAN, 46, of Upland.
JUAN ESPINOZA, 50, of Highland.