A friend of the man who opened fire at an office party in San Bernardino earlier this month is expected to face criminal charges.

Gun charges are expected to be filed Thursday against 24-year-old Enrique Marquez, according to the Washington Post. It's unconfirmed if the suspect has been arrested as of yet.

Marquez, former neighbor to San Bernardino shooter Syed Rizwan Farook, allegedly bought two of the assault rifles used in the deadly attack on Dec. 2 that killed 14 people and wounded 22 others.

A news conference is scheduled later Thursday in San Bernardino.

Authorities raided Marquez's home in Riverside on Dec. 5, three days after San Bernardino shooting. Two days prior to the raid, Marquez posted a message to Facebook.

"I'm. Very sorry sguys [sic]. It was a pleasure," read the muddled post.

Marquez's coworkers at the neighborhood, pirate-themed bar where he was employed worried when he didn't show the next day. They feared he had become suicidal, as he had checked himself into a mental-health institution shortly after the San Bernardino attack.

According to U.S. law enforcement officials, Marquez had been drinking heavily when he admitted himself into the facility.

NBC News reports Marquez purchased the assault rifles two years before the shooting. Marquez claims he did it as a favor to his friend Farook, so that he could avoid background checks, and so he wouldn't be registered as a purchaser.

Marquez mentioned that he did discuss the possibility of staging an attack with Farook in 2012, but abandoned the idea after an unrelated terrorism investigation resulted in the arrest and conviction of four local men in Riverside.

Investigators are trying to determine whether Marquez had any relation to the earlier terror plot in Riverside, though FBI Director James Comey said they found no connection with Farook and the four men arrested back then.