Inside the Christmas party that preceded San Bernardino massacre

THEY’D just eaten Christmas lunch, and everyone was congratulating Syed Farook. But then something made him flip.

IT was meant to have been a day of celebration.

End of year festivities were underway and there were awards to be distributed at the Inland Regional Center where Christmas decorations were hanging in the halls and a bright tinsel-wrapped tree stood at the entrance.

It was the local Department of Health’s Christmas party — a lunchtime gathering of San Bernardindo County co-workers.

One of the revellers was Syed Farook, an employee of the department for around five years who had recently returned from paternity leave. The 28-year-old was being congratulated on the arrival of his and his new wife’s six-month-old baby, one of the attendees later said. The same colleagues had reportedly thrown Farook a baby shower ahead of his joyous arrival.

By all reports, proceedings went as planned until Farook made the decision to leave the party, possibly after an argument. A colleague seated at the same table as Farook said he left suddenly, leaving his coat on his chair.

Patrick Baccari told the LA Times a staff photo was about to be taken of the happy group of co-workers when he noticed Farook gone.

“I guess he’s missing the photo this year,” Mr Baccari remembers thinking to himself.

An undated photo of San Bernardino shooting suspect Syed Rizwan Farook, 28, obtained by ABC News on a Muslim-oriented dating site. Syed Farook.

But Farook would return, this time with his wife, Tashfeen Malik, 27, both of them armed to the teeth and dressed in full combat gear to slaughter those who had earlier celebrated with him.

Fourteen people were killed and a further 21 left injured when as many as 75 rifle rounds fired during the massacre — the worst shooting rampage the US has seen since Sandy Hook in 2012.

Disturbingly, the husband-and-wife shooters also left behind three rigged-together pipe bombs and a remote-control explosive device that had apparently malfunctioned.

They also had more than 1600 bullets on them when they were eventually gunned down in a dramatic police shootout hours later, indicating the attack could have been much worse.

Survivors, some recovering from bullet wounds and others from shock, were surprised their quiet co-worker was capable of such a massacre.

“That doesn’t make sense,” injured health worker Julie Swann-Paez said as she woke after surgery following the attack.

“They were congratulating him for having a baby.”

A former employee of the health department, Griselda Reisinger said: “He never struck me as a fanatic, he never struck me as suspicious.”

The shooter’s brother-in-law, speaking on behalf of the family, said he had “no idea” why he would have done it.

Farhan Khan, left, brother-in-law of one of the suspects involved in a shooting in San Bernardino. Picture: Matt Masin/The Orange County Register via AP

Two women comfort each other near the scene of the shooting outside a southern California. Picture: KNBC via AP

While co-workers reported Farook held no obvious grudges in the office, CNN reports law enforcement sources cited workplace grievances as part of the mass-murderer’s motivation.

Authorities have conceded the possibility “mixed motives” were at play as a wide-ranging investigation began.

Farook was born in the US to a Pakistani family and endured a turbulent home life, according to court records seen by the LA Times.

Malik came to the US on a Pakistani passport and a fiancee visa in July 2014.

The pair had left their six-month-old baby with Farook’s mother before returning to the Inland Regional Centre on Wednesday afternoon, saying they had to go to a doctor’s appointment.

The black SUV that was used by Farook and Malik after the attack San Bernardino. Picture: CNN

In divorce filings, Farook’s mother detailed a violent and abusive marital history with her “negligent and alcoholic” husband, and said the children occasionally had to intervene.

The FBI is also investigating possible terror links, with the New York Post reporting Farook was in contact with more than one international terror subject and may have been recently radicalised.

“There was obviously a mission here. We know that. We do not know why. We don’t know if this was the intended target or if there was something that triggered him to do this immediately,” said David Bowdich, assistant director of the FBI’s Los Angeles office.

At the White House, President Barack Obama said after meeting with his national security team that it was “possible this was terrorist-related” but that authorities were unsure.

Law enforcement experts said investigators may well conclude the killers had more than one motivation.