Authorities said Thursday they are still looking for a motive behind the deadliest U.S. mass shooting in nearly three years, even as they revealed that the attackers had amassed a stockpile of explosives and ammunition.
The FBI has taken over the investigation, with authorities scrutinizing three crime scenes: The Inland Regional Center, the site of the mass shooting; the street in San Bernardino where the police and the suspects had their gun battle; and the rented home in Redlands where authorities said the suspects had an arsenal of pipe bombs and thousands of rounds of ammunition.
Police said Syed Rizwan Farook, 28, a county health worker born in Chicago, and Tashfeen Malik, 27, his Pakistani wife in the U.S. on a visa, were both dressed in tactical gear and armed with rifles, handguns and multiple ammunition magazines when they strode into a holiday party for county workers Wednesday morning.