San Bernardino shooting: Suspects dropped off six-month-old daughter with relative before embarking on killing spree

The little girl was left with a grandmother in the nearby town of Redlands

The property in Redlands that has become a focus of the police investigation (Getty)

There was one final task for Rizwan Farook and his wife Tashfeen Malik, before they set embarked on a killing spree that has rocked the nation - drop off their six-month old daughter with a relative.

Amid the chaos and bewilderment that has set in following Wednesday’s shooting - and the ongoing search for motive - officials and family members are struggling to make sense of their actions.

Shortly before they entered the Inland Regional Centre in San Bernardino, heavily armed and wearing masks, they visited Mr Farook’s mother in the nearby city of Redlands and left their child with her. They told her they had a medical appointment.

Farhan Khan spoke on Wednesday night (AP)

“Why would he do something like this? I have absolutely no idea. I am in shock myself,” Ms Malik’s brother-in-law, Farhan Khan, said, according to the Los Angeles Times.

“I just cannot express how sad I am for what happened today. I’m very sad that people lost their life and there are victims out there.”

The grandmother grew worried when she heard of the shooting and “she started calling and go no answer. She then started receiving calls from the media, asking if she knew her son was a suspect in the shooting in the neighboring town.

“I just cannot express how sad I am for what happened today,” Mr Khan added, speaking at a press conference held by the Muslim advocacy group the Council on American-Islamic Relations on Wednesday night.

“I am in shock that something like this could happen.”

Mr Khan said he had spoke to Mr Farook a week ago, adding: “Why would he do something like this?” He added that Mr Farook, who worked as a health inspector for the county health department for five years, and Ms Malik had been married for about two years.

San Bernardino Police Chief Jarrod Burguan told reporters on Wednesday night that the couple had entered the building heavily armed, wearing masks and “tactical gear”.

“These people came prepared to do what they did as if they were on a mission,” Burguan said. “They were armed with long guns, not with handguns.”

The couple fled the scene of the shooting in a black SUV. It was intercepted by police back in the city of Redlands, raising the possibility that the couple were going to retrieve their daughter.

As it was, they were shot dead by police after a shoot-out that played out on a street and captured by television helicopter cameras.