SAN BERNARDINO, California - The FBI and police are searching the Redlands townhome tied to San Bernardino shooting suspect Syed Rizwan Farook. Late Wednesday night, police used a battering ram to enter the home and sent a robot in to sweep for possible explosives.

Police have identified Farook, a 28-year-old American citizen born in Chicago and employee with the San Bernardino County Department of Health, and Tashfeen Malik, a 27-year-old female who is Farook's wife, as the two suspects involved in the shooting

Police said Farook was at a holiday banquet with coworkers before leaving abruptly and returning with his wife. Shortly after, shots were fired, reports CBS News' David Begnaud.

"I am in shock that something like this could happen," said Farook's brother-in-law, Farhan Khan.

Khan told CBS News that Farook and Malik were married for two years and had a 6-month-old child, who they left with Farook's mother.

Farook traveled to Saudi Arabia for two weeks in July 2014 to pick up his fiancee, Malik, who is Pakistani, a law enforcement source told CBS News. Malik received a K1 Visa, known as a fiance visa, a U.S. official told CBS News. It's unclear when the visa was issued.

A source told CBS News that they were looking at ISIS propaganda online.

At a press conference with local Muslim leaders, Khan offered his condolences to the families of the victims and expressed his disbelief.

"I have no idea why would he do that? Why would he do something like this. I have absolutely no idea," Khan said.

Farook and Malik were killed in the police pursuit that ended in a shootout.

A federal law enforcement official tells CBS News both were dressed in tactical clothing, armed with assault rifles, and each had multiple magazines of ammunition attached to their clothing. Police also discovered handguns in their SUV.

The Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) confirmed all four guns used in the attack were traced and purchased legally, reports CBS News' Justice Department reporter Paula Reid. Two of the guns were purchased by an unnamed person known to the investigation, officials said. The other two were purchased by an unknown individual.

Law enforcement officials do not have a motive yet, but say they are not ruling out terrorism. Police say they are confident the two suspects killed were the only shooters involved.

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