A federal grand jury today indicted Enrique Marquez Jr., the Riverside man already charged in connection with the Dec. 2 terrorist attack in San Bernardino, adding two new charges of making false statements regarding the purchase of two assault rifles used in the shooting.

The five-count, seven-page indictment charges Marquez, 24, with conspiring with San Bernardino shooter Syed Rizwan Farook, to provide material support to terrorists; lying about the purchase of two assault rifles — a 5.56-caliber Smith and Wesson, model M&P-15 Sport, and a 5.56-caliber DPMS, model A-15 — that Farook and his wife, Tashfeen Malik, used in the shootings; marriage fraud; and making a false statement on immigration paperwork regarding the sham marriage.

“This indictment demonstrates that we will hold accountable all individuals who collaborate with terrorists in executing their plans,” said U.S. Attorney Eileen M. Decker in a statement. “Defendant Marquez’s extensive plotting with Syed Rizwan Farook in 2011 and 2012, and his purchase of explosive powder and two firearms, provided the foundation for the murders that occurred this month.”

Clad in tactical gear and armed with assault rifles and pipe bombs, Farook, an environmental health specialist for San Bernardino County, and Malik stormed the Inland Regional Center during an all-day training conference and holiday luncheon, opening fire and killing 14 people and wounding 22. The couple were later killed in a gunbattle with police near the intersection of San Bernardino Avenue and Richardson Street in San Bernardino.

During 10 days of questioning by FBI agents, Marquez admitted he and Farook had planned terrorist attacks in 2011 and 2012 at Riverside Community College’s cafeteria or library and on a stretch of the 91 Freeway in Riverside during rush hour, according to the Dec. 17 criminal complaint filed against Marquez.

Both Marquez and Farook were former students at Riverside Community College.

Though Marquez told investigators during questioning he had given the guns to Farook to hold onto because he could not keep them at his house, he indicated on documents when he purchased the guns that he was buying them for his or his immediate family’s personal use. He also indicated on the purchasing documents that the gun dealer explained to him that the straw purchase of a firearm was illegal, and that he was not buying the gun for anyone other than himself, according to the Dec. 17 criminal complaint.

Marquez also told investigators that in 2012 he purchased a container of smokeless powder so he and Farook could make bombs and commit mass killings. A bottle of the powder was seized from Farook’s Redlands residence following the Dec. 2 mass shooting, according to the affidavit.

“Mr. Marquez is charged for his role in a conspiracy several years ago to target innocent civilians in our own backyard with cold-blooded terror attacks, and with providing weapons to an individual whose endgame was murder,” said David Bowdich, assistant director in charge of the FBI’s Los Angeles Field Office, in a written statement Wednesday. “The covert nature of the defendant’s alleged actions is a stark reminder of the challenges we face in preventing attacks planned in the name of violent jihad, and underscores the critical need for those with knowledge about terror plots to come forward.”

On Dec. 17, the day Marquez was arrested and charged with the first three counts, he stopped talking to investigators without his attorney present, court records show.

“I do not wish to, and will not, waive any of my constitutional rights except in the presence of counsel,” said the court document signed by Marquez on Dec. 17. “I do not want the government or others acting on the government’s behalf to question me, or to contact me seeking my waiver of any rights, unless my counsel is present.”

U.S. Attorney’s Office spokesman Thom Mrozek said via email Wednesday that Marquez was initially charged in a criminal complaint, which is a charging document supported by a sworn affidavit by a law enforcement officer.

“Once a defendant has been taken into custody on a complaint, she/he is entitled to a probable cause hearing in which an independent agency reviews the evidence to determine if there is probable cause that the defendant committed the crime,” Mrozek said. “Probable cause hearings are conducted in one of two ways — a preliminary hearing before a judge, or a grand jury proceeding. In this case, we presented evidence to a grand jury, which made the probable cause finding and issued a ‘true bill’ — the indictment, which was filed (Wednesday) afternoon.”

Because of Wednesday’s indictment, the preliminary hearing previously scheduled for Monday will be taken off the calendar, Mrozek said.

Marquez was charged and subsequently appeared in court on Dec. 17. He has not entered a plea but is expected to do so in an arraignment Wednesday in U.S. District Court in Riverside. He is being held without bail.