(CNN) -- Federal prosecutors are expected to file charges against a friend and former neighbor of San Bernardino attacker Syed Rizwan Farook, law enforcement officials told CNN Thursday.
The charges against Enrique Marquez are expected to partly be based on allegations that Marquez had bought two rifles that Farook and Farook's wife used in the December 2 mass shooting that left 14 people dead in the Southern California city.
Marquez, 24, has told investigators he didn't know about the plans for the San Bernardino attack, U.S. officials have said.
But he has acknowledged that he bought the two AR-15s for Farook several years ago, and he told investigators about a 2012 attack plot that he says he and Farook conceived but did not carry out, U.S. officials told CNN.
Since the San Bernardino shootings, he has waived his Miranda rights, cooperated with investigators and provided information, according to the officials.
CNN's Scott Glover and Lorenza Brascia contributed to this report.
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