What We Know About San Bernardino Shooter's Alleged 'Rush Hour' Terror Plot

— -- Four years before Syed Rizwan Farook and his wife Tashfeen Malik killed 14 people at an office party in San Bernardino, Farook plotted with his old friend and neighbor Enrique Marquez to kill as many people as possible during a “rush hour” attack on a highway in California, according to the FBI.

The late 2011 or early 2012 plot was detailed for the first time today in a criminal complaint filed against Marquez, who authorities said admitted the plans during a 10-day questioning session with the FBI after the San Bernardino shootings earlier this month.

According to the complaint, Marquez told the FBI that he had converted to Islam in 2007 and was pushed towards radical Islamic material by his friend and neighbor Farook. In late 2011, the two decided to strike in the U.S., and discussed whether they should attack a local community college and busy California highway, SR-91.

Marquez allegedly pointed out to federal agents exactly where the attack on the highway was supposed to have taken place and how it would go down.

“Marquez admitted that prior to the attack, he would first deploy to the hills south of the freeway as an overwatch for Farook,” an FBI affidavit in the complaint says. “Farook then would start the attack by throwing pipe bombs into the eastbound lanes of SR-91. Both Marquez and Farook believed that the exploding pipe bombs would disable and stop traffic.”

“After deploying the explosive devices, Farook planned to move among the stopped vehicles, shooting his rifle into them, and killing people,” it continues. “Marquez stated that he planned to shoot into the stopped vehicles from his position on the hills while watching for any approaching law enforcement or emergency responders. According to Marquez, his priority was to shoot law enforcement personnel before shooting life-saving personnel.”

The FBI says Farook and Marquez got as far as buying weapons -- including two semi-automatic AR-15 rifles that Marquez purchased in November 2011 and February 2012 -- as well as smokeless powder “in furtherance of his and Farook’s plans to create bombs and commit mass killings.” Marquez said that he bought the rifles "because his appearance was Caucasian, while Farook looked Middle Eastern." The two also went to shooting ranges to practice, the complaint says.

But luckily for motorists, the plans fizzled out. The FBI says that in 2013, Farook and Marquez’s “contact began to decline and according to Marquez they ceased planning any attacks together.”

Farook and his wife Tashfeen Malik, however, carried on and murdered 14 people at San Bernardino’s Inland Regional Center on Dec. 2. The couple was killed by police four hours after the shooting.

Marquez was charged today with “conspiring to provide material support to terrorists” in relation to the aborted community college and highway plots, and with making a “straw purchase” of the two rifles that were later used in the San Bernardino attacks – but he was not charged with being directly involved in the San Bernardino attack.

In a dramatic 911 call hours after the shooting, Marquez told the emergency operator he was considering killing himself.

“My neighbor, he did the San Bernardino shooting,” Marquez purportedly said, according to a transcript of the call in the complaint. “He was the shooter… F***ing a**hole used my gun in the shooting… They can trace all the guns back to me.”

Marquez told the operator he had given Farook the gun “only for safe storage” because he couldn’t have it at home with his little brothers around, the court documents say.