Neighbor of San Bernardino shooter has been arrested: official

Enrique Marquez, a neighbor and friend of one of the San Bernardino shooters, has been arrested in connection with the investigation, a law enforcement official confirmed to ABC News.

The nature of the arrest and the charges that he faces were not immediately known.

Investigators have said that Marquez, 24, bought the two rifles used in the deadly Dec. 2 attack that left 14 people dead and injured 20 others.

Officials have said they believe one of the San Bernardino gunmen, Syed Rizwan Farook, asked Marquez to buy the two “assault-style” rifles back in late 2011 or early 2012.

In a Facebook posting from Marquez’s profile just hours after the attack, he said, “I’m. Very sorry sguys. It was a pleasure.”[sic]

The FBI has questioned Marquez and he has provided the agency with information not previously known, federal officials said earlier this month.

“He’s continued to cooperate with investigators since they got ahold of him,” a counter terrorism official familiar with the investigation told ABC News.

The two suspects — Farook and wife Tashfeen Malik — were killed in a shootout with police shortly after the initial attack at the Inland Regional Center.

Marquez’s mother and brothers declined earlier this month to discuss the investigation, but friends of Marquez told ABC News he is a “great guy.” Viviana Ramirez, who went to school with Marquez, said she thought it was a joke when she heard his name linked to the San Bernardino tragedy.

ABC News’ Jack Date and Pierre Thomas contributed tot his report.