Transcript for San Bernardino Shooter's Neighbor Charged
And we begin tonight with that terror arrest late today in connection with the horror that unfolded in San Bernardino. The husband and wife, turned killers at that work holiday party. Well, tonight, Syed farook's childhood friend, Enrique Marquez, under arrest, after being questioned for days. Authorities tonight revealing the stunning charges. They say he was the friend who bought those assault weapons and had trained with farook before. Among the plots they allegedly hatched, a plan to trap drivers during rush hour and then unleash their terror. We begin with ABC's chief investigative correspondent Brian Ross tonight. Reporter: After ten days of questioning by the FBI at a secret location, Enrique Marquez was brought to the federal courthouse in Riverside, California, late today, in the back of this FBI vehicle to face serious terror charges. Within hours of the San Bernardino terror rampage, the FBI figured out that the two assault rifles used in the attack were bought by Marquez, almost four years ago. But the charges made public today reveal the 24-year-old Marquez and his long-time friend and former next door neighborhood, Syed farook, first planned to use the weapons and pipe bombs to attack the ca cafeteria of a community college in late 2011 or early 2012. And then, later, for a rush hour terror attack on this California freeway. Quote, the plan was for farook to throw pipe bombs onto the highway. And then, move into vehicles. According to the federal complaint, it was farook who per swalded mar kedz to convert to Islam some eight years ago and radicalized him using online videos from Al Qaeda. Authorities also charge that farook got Marquez to marry a Russian woman who was an extended member of farook's family, so she could come to the United States. Marquez confided to his friends, it was all a sham. He just said he married her for the Visa. And that's pretty much where he left it. Reporter: More ominously in the weeks before the terror attack that killed 14 people in San Bernardino, friends say Marquez warned of the plans of what he called a terror sleeper cell. He would just, you know, talk about how there are so many sleeper cells and when it's going to happen, it's going to be big. Reporter: Two days after the attacks, Marquez wrote on Facebook, "My life turned ridiculous, involved in terrorist plots, drugs, anti-social behavior, marriage. Might go to prison for fraud, et cetera." And Brian Ross is with us now. We want to be clear here. Marquez is not accused of participating in the San Bernardino attacks? Reporter: That's right, David. Federal prosecutors say there is currently no evidence that Marquez was part of the attacks. But there's no doubt buying the rifles for farook clearly had fatal con consequences. If convicted on today's charges, he could face up to 35 years in prison, David. All right, Brian Ross on this every step of the way.
This transcript has been automatically generated and may not be 100% accurate.