WASHINGTON: She was so private and conservative that there are no photographs of her even though she operated a Facebook account under a false name. Even her in-laws never saw her outside a full-faced orthodox burka. And nursing a newborn infant at home didn't stop her from stocking up an arsenal at home, under cover and possibly with help from a husband, who she knew, always been interested in shooting and weapons, and who she likely radicalized.

In a dramatic twist to the San Bernardino shooting case that resulted in 35 casualties, including 14 dead, investigators are now focusing on Tashfeen Malik, the 27-year Pakistani wife of Syed Rizwan Farook, who reportedly pledged allegiance to ISIS on the day of the carnage through a fake Facebook account. The Pakistani media is also reporting that US officials have found Tashfeen had ties to clerics of the Lal Masjid in Islamabad, an extremist hub that was attacked during the Musharraf regime resulting in scores of casualties, including many women, and an eruption in extremist anger.

READ ALSO:

California shooters kept tight lid on their plans, stockpiled weapons

US special envoys are said to have briefed Pakistan's Prime Minister Nawaz Sharif in London and demand action against the extremists, ARY TV reported on Friday, suggesting there was a great deal of panic in the Pakistani government over its coddling of terrorism over many years. Pakistan has produced, sheltered, and also given up more prominent terrorists than any other country in the world, from Ramzi Yousef, who tried to bring down the World Trade Center in 1993, to Khalid Sheikh Mohammed and Osama bin Laden, to Hafiz Saeed and Zakiur Lakhvi, the last two still thriving under Pakistan's protection.

Meanwhile, US investigators are starting to piece together the sequence of events that allowed Tashfeen Malik to infiltrate the United States through a route that is used by thousands of singles every year who get engaged to US citizens. While the family of Syed Rizwan Farook maintains that they saw no sign that he had been radicalized at any time, it appears that when he went online to look for an orthodox, conservative wife, he ran into the profile of Tashfeen, then living in Saudi Arabia. She may already have been radicalized, and possibly baited him giving her a safe passage to America. One of his online profiles mentioned he is interested in recreational shooting and target practice.

Sketchy reports about own Tashfeen's background indicates that she lived in Saudi Arabia from the time her father mover there when she was a child. She returned to Pakistan to study pharmacy at the Bahauddin Zakariya University in Multan. The university is named after a Sufi mystic, but Multan itself is considered part of a radicalized Southern Punjab region in Pakistan where sunni militancy is at a toxic high. It is not clear yet whether she got radicalized here or in Saudi Arabia, or both.

Following Tashfeen's arrival in the US., it appears Farook may also have became radicalized (by her). One co-worker told CBS that the wife definitely radicalized him and he essentially "married a terrorist." Always devout (according to his father), he also grew a beard, and, according to some reports, got into frequent arguments with co-workers on religion and politics. According to one account, Farook wrangled with a co-worker, a Messianic Jew named Nicholas Thalasinos, who was a strong votary of Israel and frequently criticized Islam. Thalasinos was one of the 14 victims killed in the carnage. They may have gotten into arguments in the days leading up to the carnage and even on the day of the massacre.

While US officials have confirmed that Tashfeen was given a K1 fiancee visa in Islamabad after due process, it is not clear if Farook accompanied her to Pakistan or to the visa interview. Putative spouses are required to furnish documentation about engagement but are not required to be present at the interview. Like all K1/Fiancee visa applicants, Tashfeen was vetted for extremist connections but there were no red flags, according to the State Department.

READ ALSO: California gunman's Pak wife had pledged allegiance to IS

The K1 fiancee visa with which Tashfeen entered the United States is now at the center of conservative, Republican wrath, with some lawmakers suggesting it has opened up a new route for terrorist infiltration. The visa enjoins engaged couples to be married within three months of entering the US., a condition the Farook and Tashfeen evidently complied with, although no reports or photos of the wedding have surfaced so far. Apparently, Tashfeen was so orthodox that even Farook's own family never saw her without a veil.

Meanwhile, it transpires that Tashleen's father Malik Gulzar Aulkah also moved to the United States. It is not known if she had anything to do with his emigration. According to one account, she was recently granted a two-year provisional green card that spouses of American citizens are eligible for immediately after marriage. That provisional green card becomes a long-term 10-year permanent residency after the couple prove they have been together for two years.

One other intriguing aspect of their alliance: Farook uploaded his profile on iMilap, an online matrimonial website for people with disabilities and those seeking a second marriage. It is not clear if either or both of them had any disability or were into their second marriage.

Farook also worked part time in the regional center that cared for people with disability, the same place he and wife attacked, killing 14 and injuring 21.