A week-old investigation into the shooting rampage that left 14 people dead at a holiday party in Southern California turned on Thursday night to a small lake near the scene of the massacre, where divers searched for evidence.
The FBI also revealed investigators were looking into any connections there may have been between one of the two killers in San Bernardino last week and four men arrested in 2012 in a separate federal terrorism case brought in nearby Riverside, California.
Thursday's underwater search stemmed from unspecified leads indicating the married couple who carried out the shooting spree had been in the vicinity of Seccombe Lake in San Bernardino on the day of the killings, said David Bowdich, assistant director of the FBI field office in Los Angeles.
Mr Bowdich said he would not discuss the “specific evidence we’re looking for.”
CNN reported investigators were seeking a computer hard drive that belonged to the couple, who the FBI has said were inspired by Islamic extremists. Bowdich said investigators already have combed the surrounding park, and that the search of the lake by FBI and Sheriff’s Department divers could take days.
Seccombe Lake Park lies about 4 km north of the Inland Regional Center, the social services agency where 14 people were killed and 22 others injured when Syed Rizwan Farook and his wife, Tashfeen Malik, stormed a holiday gathering of his co-workers there on Dec. 2 and opened fire with assault rifles.
Farook (28), a US-born son of Pakistani immigrants, and Malik (29), a Pakistani native he married last year in Saudi Arabia, were slain hours after their attack in a shootout with police.
The FBI said it is treating the mass shooting as an act of terrorism, citing the couple’s declaration that they were acting on behalf of the militant group Islamic State, as well as a large cache of weapons, ammunition and bomb-making materials seized in the investigation.
The couple’s motives remain unclear. But if the crime proves to have been the work of killers driven by militant Islamic ideology, as the FBI suspects, it would mark the deadliest such attack on US soil since September 11th, 2011.
The latest slayings and disclosures about the killers’ backgrounds have put law US law enforcement on heightened alert and reverberated into the US presidential campaign, intensifying debates over gun control, immigration and national security.
Speaking to reporters at Seccombe Lake on Thursday, Mr Bowdich disclosed the FBI was examining whether Farook had any links with the four conspirators in the Riverside case, as CNN and other media outlets have reported.
A jury last year convicted two of those men, including Afghan-born ringleader Sohiel Omar Kabir, of conspiring to provide material support and resources to al Qaeda and plotting to attack US military forces in Afghanistan.
Their two co-defendants pleaded guilty in the case.
Reuters