By Evan Perez and Jason Hanna
(CNN) — A friend and former neighbor of San Bernardino, California, attacker Syed Rizwan Farook was arrested by the FBI on Thursday and faces three charges.
Enrique Marquez, 24, is accused of conspiring with Farook to provide material support to terrorism, making a false statement in connection with the acquisition of firearms, and immigration fraud, according to a statement from the Department of Justice.
He is believed by authorities to have bought two assault rifles used by Farook and Farook’s wife, Tashfeen Malik, in the December 2 mass shooting and terror attack that left 14 people dead in the Southern California city.
Marquez is expected to make an initial appearance in court on Thursday afternoon. He 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 said 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 Malik opened fire on Farook’s co-workers at a work event December 2. Police shot and killed them hours later.
The massacre was a terror attack, authorities have said. 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.
Neighbors, rifles and pipe bombs
Marquez and Farook were neighbors in Riverside, California, until Farook and Malik moved recently to nearby Redlands. Investigators have been delving into Marquez’s relationship with Farook, but authorities have not accused him of plotting or knowing about plans for the San Bernardino attack.
Marquez was a state-licensed security guard until his license expired last year. At one point he converted to Islam and attended the same mosque as other members of the Farook family, though a mosque facility manager told CNN that Marquez stopped attending the mosque about two years ago.
Marquez bought one rifle in 2011 and another later, and gave both to Farook but did not report the transfer of ownership, two law enforcement officials told CNN on condition of anonymity.
He also told investigators that he used to build pipe bombs with Farook, portraying himself and his friend as hobbyists experimenting with building the devices, law enforcement officials said.
Marquez said he had nothing to do with the pipe bombs that authorities found at Farook’s home after the December 2 attack, or the ones that apparently failed to go off at the site of the shooting, the officials said.
Marquez also told investigators that he and Farook were planning a terror attack in 2012, and that the two abandoned their plans in part because they were spooked by the arrests of four Riverside-area men charged with attempting to travel abroad to carry out jihad, officials told CNN on condition of anonymity.
Farook knew at least one of those men, officials told CNN.
Talking to CNN last week, neighbors of the Riverside homes where Marquez and Farook lived next door to one another recalled the two working on cars together but did not know whether their relationship extended beyond that shared interest.
As for the killers, the bodies of Farook and Malik were buried Tuesday, 13 days after the attacks, according to the Law Offices of David S. Chesley, the California attorney who represents Farook’s family. A funeral for the couple Tuesday in Rosamond, north of Los Angeles, was attended by family members and “very few” friends, a source told CNN on condition of anonymity.
President Barack Obama is expected to travel to San Bernardino on Friday to meet privately with families of the victims of this month’s attack.
CNN’s Scott Glover and Lorenza Brascia contributed to this report.