AP - In the final few years of Tashfeen Malik's life, the people around the young woman saw her dress ever more conservatively and urge people ever more ardently to live a devout life.

For an aunt in Malik's old hometown of Pakistan, Malik's growing religious focus was one of the last things the aunt heard about her 29-year-old niece — before last week, when the relative learned that her niece and her niece's husband had donned face masks, hoisted assault rifles and killed 14 people in a rampage in Southern California.

"I recently heard it from relatives that she has become a religious person, and she often tells people to live according to the teachings of Islam," recalled aunt Hifza Batool.

Batool spoke in the town of Karor Lal Esan, the home of Malik's family, 280 miles (450 kilometers) southwest of the Pakistani capital of Islamabad.

Who was Tashfeen Malik? Credit: MSNBC

Malik's path from Pakistan to the bloody events of this past week — when she and her husband slaughtered people gathered for a holiday work party — remains a mystery.

FBI officials, family lawyers and others said they know little about the housewife and mother, apart from what came to light on Friday: that Malik had pledged allegiance to ISIS on Facebook as she and her American-born husband, Syed Farook, 28, launched the massacre.

The husband and wife were killed in a furious shootout with police hours after they opened fire on a gathering of Farook's colleagues from the San Bernardino County public health department, where he worked as a restaurant inspector.

The FBI said it is investigating the rampage as a terrorist attack.

President Barack Obama plans to deliver a prime-time address to the nation Sunday night on the attack and the government's efforts to keep the nation safe.

Early on Saturday, authorities with guns drawn raided a home next door to the house where Farook's family used to live in Riverside, California, breaking windows and using a cutting torch to get into the garage, neighbors said.

The FBI would not say what it was looking for, but a neighbor said an old friend of Farook's lives there.

More than three years ago, that person bought the two assault rifles later used in the shooting, but authorities haven't been able to talk to him because he checked himself into a mental hospital after the attack, said a law enforcement official who was not allowed to discuss the investigation and spoke on condition of anonymity.

The FBI has said the man is not a suspect in the shootings, though they want to question him.

U.S. officials said that Farook had been in contact with extremists via social media. One official said those contacts were not recent and did not involve any significant players on the FBI's radar.

Farook was born in Chicago to Pakistani parents and raised in Southern California. Malik arrived in the U.S. in 2014 on a Pakistani passport and a fiancee visa but had spent extended periods of time in Saudi Arabia.

She started studying pharmacy at Bahauddin Zakariya University in the Pakistani city of Multan in 2012.

A maid who worked in the Multan home where Malik lived said that Malik initially wore a scarf that covered her head but not her face.

A year before she got married, she began wearing a scarf that covered all but her nose and eyes, the maid said. The maid spoke on condition of anonymity for fear of jeopardizing her employment with the family.