Meredith Davis, a spokeswoman for the Bureau of Alcohol, Tobacco, Firearms and Explosives, said officials had "successfully traced" the four guns recovered in connection with the San Bernardino shooting and determined that two of the weapons were purchased legally.
The guns were bought by an individual associated with the investigation, Davis said but declined to name the person.
"Agents continue to investigate leads concerning the two additional firearms," Davis said.
Police officials said that two suspects, Syed Farook and Tashfeen Malik, were armed with two semiautomatic rifles and two semiautomatic handguns.
The semiautomatic rifles were a .223-caliber DPMS Model A15 and a Smith & Wesson M&P15. One of the handguns was manufactured by Llama, and the other by Smith & Wesson.
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