San Bernardino shooter’s social media posts on jihad were obscured

Evan Perez Dana Ford
By Evan Perez and Dana Ford, CNN
Updated 11:37 PM EST, Mon December 14, 2015
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SAN BERNARDINO, CA - DECEMBER 03: FBI agents and local law enforcement examine the crime scene where suspects of the Inland Regional Center were killed on December 3, 2015 in San Bernardino, California. Police continue to investigate a mass shooting at the Inland Regional Center in San Bernardino that left at least 14 people dead and another 17 injured. (Photo by Sean M. Haffey/Getty Images)
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SAN BERNARDINO, CA - DECEMBER 02: SWAT officers enter an area where suspects were believed to be after the shooting at the Inland Regional Center on December 2, 2015 in San Bernardino, California. Police continue to search for suspects in the shooting that left at least 14 people dead and another 17 injured. (Photo by Sean M. Haffey/Getty Images)
SAN BERNARDINO, CA - DECEMBER 02: SWAT officers enter an area where suspects were believed to be after the shooting at the Inland Regional Center on December 2, 2015 in San Bernardino, California. Police continue to search for suspects in the shooting that left at least 14 people dead and another 17 injured. (Photo by Sean M. Haffey/Getty Images)
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Story highlights

Tashfeen Malik advocated jihad in messages on social media

Her comments were made under a pseudonym and with strict privacy settings

Authorities are working to trace the electronic trail of Malik and her husband

CNN  — 

Tashfeen Malik advocated jihad in messages on social media, but her comments were made under a pseudonym and with strict privacy settings that did not allow people outside a small group of friends to see them, U.S. law enforcement officials told CNN on Monday.

Malik and her husband, Syed Rizwan Farook, opened fire on the latter’s co-workers at a work event on December 2 in San Bernardino, California, killing 14.

Authorities are working to trace the electronic trail of the killers and trying to find out whom they interacted with, how they hatched and carried out the plot, and why.

Police officers stand guard as they investigate a suspicious vehicle in Redlands, California, on Wednesday, December 2, after a mass shooting in nearby San Bernardino in which 14 people died and 21 were injured. The shooting took place at the Inland Regional Center, where employees with the county health department were attending a holiday event. The two shooters -- Syed Rizwan Farook and his wife, Tashfeen Malik -- were fatally shot in a gun battle with police hours after the initial incident. Farook worked for the county health department.
Photos: San Bernardino shooting
Justin Sullivan/Getty Images
Police officers stand guard as they investigate a suspicious vehicle in Redlands, California, on Wednesday, December 2, after a mass shooting in nearby San Bernardino in which 14 people died and 21 were injured. The shooting took place at the Inland Regional Center, where employees with the county health department were attending a holiday event. The two shooters -- Syed Rizwan Farook and his wife, Tashfeen Malik -- were fatally shot in a gun battle with police hours after the initial incident. Farook worked for the county health department.
A police officer places a marker along East San Bernardino Avenue, near where the shootout occurred.
Photos: San Bernardino shooting
Rick Loomis/LA Times via Getty Images
A police officer places a marker along East San Bernardino Avenue, near where the shootout occurred.
Law enforcement officers search a residential area for suspects who fled after the shooting.
Photos: San Bernardino shooting
PATRICK T. FALLON/AFP/Getty Images
Law enforcement officers search a residential area for suspects who fled after the shooting.
Police search for the suspects in San Bernardino.
Photos: San Bernardino shooting
PATRICK T. FALLON/AFP/Getty Images
Police search for the suspects in San Bernardino.
The residential area was not far from where the shooting occurred.
Photos: San Bernardino shooting
PATRICK T. FALLON/AFP/Getty Images
The residential area was not far from where the shooting occurred.
Law enforcement officers search a neighborhood in San Bernardino.
Photos: San Bernardino shooting
EUGENE GARCIA/EPALandov
Law enforcement officers search a neighborhood in San Bernardino.
A police officer loads his weapon while pursuing suspects.
Photos: San Bernardino shooting
Francine Orr/Los Angeles Times/Getty Images
A police officer loads his weapon while pursuing suspects.
A SWAT team mobilizes during the search.
Photos: San Bernardino shooting
Marcus Yam/Los Angeles Times/Getty Images
A SWAT team mobilizes during the search.
People pray on the San Bernardino Golf Course, across the street from where the shooting took place.
Photos: San Bernardino shooting
Gina Ferazzi/Los Angeles Times/Getty Images
People pray on the San Bernardino Golf Course, across the street from where the shooting took place.
Heavily armed law enforcement officers swarmed the area where the shooting occurred.
Photos: San Bernardino shooting
Rachel Luna/Los Angeles News Group via AP
Heavily armed law enforcement officers swarmed the area where the shooting occurred.
People leave a community center after reuniting with friends and family in the aftermath of the shootings.
Photos: San Bernardino shooting
Jae C. Hong/AP
People leave a community center after reuniting with friends and family in the aftermath of the shootings.
A woman is comforted near the scene of the shooting.
Photos: San Bernardino shooting
Jae C. Hong/AP
A woman is comforted near the scene of the shooting.
A police helicopter hovers around the Inland Regional Center.
Photos: San Bernardino shooting
Luis Sinco/Los Angeles Times/AP
A police helicopter hovers around the Inland Regional Center.
Luis Gutierrez gets emotional as he talks about his wife who works in the facility and saw a gunman, according to Los Angeles Times photographer Marcus Yam.
Photos: San Bernardino shooting
Marcus Yam/Los Angeles Times/LA Times via Getty Images
Luis Gutierrez gets emotional as he talks about his wife who works in the facility and saw a gunman, according to Los Angeles Times photographer Marcus Yam.
Two women speak with a firefighter at a triage area near the scene.
Photos: San Bernardino shooting
Micah Escamilla/Los Angeles News Group via AP
Two women speak with a firefighter at a triage area near the scene.
Police stand guard outside of the emergency room at the Loma Linda University Medical Center, where some of the victims were being treated.
Photos: San Bernardino shooting
PATRICK T. FALLON/AFP/Getty Images
Police stand guard outside of the emergency room at the Loma Linda University Medical Center, where some of the victims were being treated.
Police escort civilians away from the site of the shooting.
Photos: San Bernardino shooting
FREDERIC J. BROWN/AFP/Getty Images
Police escort civilians away from the site of the shooting.
People walk away from the scene. It is unclear how many people were at the facility at the time of the shooting.
Photos: San Bernardino shooting
FREDERIC J. BROWN/AFP/Getty Images
People walk away from the scene. It is unclear how many people were at the facility at the time of the shooting.
Police in SWAT gear secure the area.
Photos: San Bernardino shooting
Gina Ferazzi/LA Times via Getty Images
Police in SWAT gear secure the area.
Two women embrace at a community center where family members were gathering to pick up people from the scene.
Photos: San Bernardino shooting
Jae C. Hong/AP
Two women embrace at a community center where family members were gathering to pick up people from the scene.
People gather at the San Bernardino Golf Course.
Photos: San Bernardino shooting
Micah Escamilla/Los Angeles News Group via AP
People gather at the San Bernardino Golf Course.
People talk to police at the golf course.
Photos: San Bernardino shooting
Micah Escamilla/Los Angeles News Group via AP
People talk to police at the golf course.
A woman is wheeled away on a stretcher.
Photos: San Bernardino shooting
David Bauman/The Press-Enterprise via AP
A woman is wheeled away on a stretcher.
People are moved away from the area by bus.
Photos: San Bernardino shooting
David McNew/Getty Images
People are moved away from the area by bus.
Police and fire personnel are seen near the site of the shooting.
Photos: San Bernardino shooting
Gina Ferazzi/LA Times via Getty Images
Police and fire personnel are seen near the site of the shooting.
A crowd gathers behind the police line.
Photos: San Bernardino shooting
FREDERIC J. BROWN/AFP/Getty Images
A crowd gathers behind the police line.
Ambulances pull out of a staging area near the Inland Regional Center.
Photos: San Bernardino shooting
Sean M. Haffey/Getty Images
Ambulances pull out of a staging area near the Inland Regional Center.
A SWAT vehicle carries police officers.
Photos: San Bernardino shooting
Micah Escamilla/Los Angeles News Group via AP
A SWAT vehicle carries police officers.
SWAT teams and a bomb squad were working to clear the buildings where the shootings took place.
Photos: San Bernardino shooting
FREDERIC J. BROWN/AFP/Getty Images
SWAT teams and a bomb squad were working to clear the buildings where the shootings took place.

The New York Times reported on Sunday that U.S. immigration officials conducted three background checks on Malik when she emigrated from Pakistan but allegedly did not uncover social media postings in which she said she supported violent jihad and wanted to be a part of it.

According to the law enforcement officials, because Malik used a pseudonym and privacy controls, her postings would not have been found even if U.S. authorities had reviewed social media as part of her visa application process.

A U.S. official told CNN shortly after the San Bernardino attack that the United States only recently began reviewing the social media activity of visa applicants from certain countries. The date that these types of reviews began is not clear, but it was after Malik was considered, the source said.

Visa vetting process: ’100% security difficult to achieve’

In addition to tracing what the killers said online, investigators have been working with various cell phones found either near or at the couple’s home. So far, the FBI hasn’t been able to recover data from two smashed cell phones found near the couple’s home.

They were able, however, to retrieve some data from two other phones found at the shooters’ home. Metadata showed that on the day of the attack the killers visited a park, which was the scene of an intensive lake search by FBI divers that finished over the weekend.

The search yielded nothing useful to the investigation, said a law enforcement source.

CNN’s Faith Karimi and Ana Cabrera contributed to this report.