UPDATE 11:51 a.m.: Authorities have reportedly arrestd Enrique Marquez, friend of San Bernardino gunman Syed Farook, the Los Angeles Times reported. More details to come.

RIVERSIDE (CBSLA.com) — Federal prosecutors are expected to file criminal charges against the 24-year-old former neighbor of one of the radicalized shooters who carried out the massacre in San Bernardino, CBS News said Thursday.

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At this time, it remains unclear when officials will release the nature of the charges and if Enrique Marquez will make a court appearance.

According to the FBI, Marquez purchased the two high-powered assault rifles at least three years ago, which were used by Syed Rizwan Farook, 28, and his wife, Tashfeen Malik, 27, in the terror attack.

Marquez was a childhood friend of Farook. He has confessed to plotting an attack with Farook in 2012, but said they abandoned their plans.

Marquez has been a focus of the investigation. He checked himself into a mental rehabilitation facility right after the shooting took place.

He is also married to the sister of Farook’s brother’s wife.

Farook and MalikOn Dec. 2, Farook and Malik opened fire on employees who were attending a holiday party in a conference room located at the Inland Regional Center.

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Fourteen people were killed and 22 others were injured.

COMPLETE COVERAGE: San Bernardino Shooting

Farook and Malik were killed hours later in a shootout with police, leaving behind their 6-month-old daughter.

According to the FBI, the shooters were radicalized well before Malik entered the U.S. on a fiancée visa. They had discussed jihad and martyrdom as early as 2013.

They were reportedly buried on Tuesday during a sparsely attended funeral.

According to Reuters, about 10 people attended the service in an undisclosed location, which was located hours away from San Bernardino.

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According to the White House, President Obama will visit the families of the shooting victims in San Bernardino on Friday ahead of his Christmas vacation to Hawaii.