(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 and terror attack that left 14 people dead in the Southern California city.
Details about when the charges would be filed weren’t immediately available.
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. Marquez also checked himself into a mental health facility.
Farook and his wife, Tashfeen Malik, opened fire on Farook’s coworkers at a work event December 2. Police shot and killed them hours later.
The massacre was a terror attack, authorities say. Both U.S.-born Farook and Pakistan native Malik expressed commitment to Islamic jihad and martyrdom in direct, private online messages in late 2013, months before Malik moved to the United States to live with Farook, FBI Director James Comey has said.
Malik also pledged allegiance to ISIS leader Abu Bakr al-Badghadi in a Facebook post as the San Bernardino attack was happening, three U.S. officials familiar with the investigation told CNN.
Authorities still are trying to learn more about whom the killers interacted with, how they hatched and carried out the plot and why.
President Barack Obama is expected to travel to San Bernardino on Friday to meet privately with families of the victims of the attack.