Terrorist housewife Tashfeen Malik led the charge in last week’s ISIS-inspired attack in California, firing the first shots at a group of government employees gathered around a Christmas tree, according to witness accounts reported Sunday.

The fusillade from the female jihadist’s high-powered rifle sparked chaos as bullets tore into victims who fell to the floor dead or wounded, while the Christmas tree toppled over, witnesses told the Sunday Times of London.

Meanwhile, Malik’s husband, Syed Rizwan Farook, seemed to hesitate in pulling the trigger on his co-workers — either because he temporarily chickened out or because he was searching for a specific target, the Times said.

The paper suggested Farook may have been trying to find Nicholas Thalasinos, a Messianic Jew and ardent Zionist with whom Farook had argued over his Muslim faith.

Thalasinos was among the 14 killed in the bloodbath. Another 21 people were wounded.

Witnesses said each of the black-clad killers assumed “a stance” for shooting when they entered the conference room at the Inland Regional Center in San Bernardino at around 11 a.m. Wednesday.

Malik, 29, moved to the right of the door, and Farook, 28, went to the left as they leveled their AR-15-style rifles at the holiday party that followed a training session. Farook had left about 30 minutes earlier, before the party began.

After the shooting, as workers with the county health department lay dead and bleeding, Farook stepped over them to plant a remote-controlled bomb, which did not detonate, on the table at which he had earlier been seated.

The couple, parents of a 6-month-old girl, were both killed in a shootout with cops about four hours later.

Bottles of the anti-anxiety drug Xanax and the stimulant Adderall were found on the kitchen counter back at their home in Redlands, Calif., the Times said.

Authorities suspect that Malik, who praised ISIS leader Abu Bakr al-Baghdadi on Facebook moments before the attack, “was the catalyst for sympathetic views and extreme views toward jihad in this relationship,” an official briefed on the investigation told The Post.

“They believe that she was responsible for radicalizing Farook, and they believe that this happened over a period of time during their marriage,” the official said.

“It just didn’t happen overnight. It took some time, but she was able to instill her sick, twisted views into his mind.”

A former co-worker of Farook’s endorsed that notion, saying he noticed a change in Farook’s personality after his August 2014 wedding to Malik in Saudi Arabia.

“I think he married a terrorist,” Christian Nwadike told the Times.

Farook, who was born in Illinois, met Malik online. She was born and raised in Pakistan but moved to Saudi Arabia as an adult.

A relative who lives in Malik’s hometown of Karor Las Esan, Pakistan, told the Los Angeles Times that Malik began posting extremist messages on Facebook that alarmed her family shortly after she arrived in the United States.

The relative said Malik had once been a “modern girl” but embraced her Islamic faith while in college and “started asking women in the family and the locality to become good Muslims.”

“She used to talk to somebody in Arabic at night on the Internet. None of our family members in Pakistan know Arabic, so we do not know what she used to discuss,” the relative said.

Farook’s dad, also named Syed, told the Italian newspaper La Stampa that his son supported ISIS and was fixated with the idea of fighting Israel.

“My son said that he shared al-Baghdadi’s ideology and supported the creation of the Islamic State. He was also obsessed with Israel,” the father said.

Farook’s father described his son as “very religious.”

“Once we had a dispute over the historical figure of Jesus,” he said, according to a translation by the Times of Israel.

“My son called me a godless person, and he decided that my marriage with my wife had to end,” added the elder Farook, who was divorced by his son’s mother, Rafia, in 2006 over allegations of alcoholism and abuse.