RIVERSIDE, California (REUTERS) - The man who supplied guns to the couple who killed 14 people in San Bernardino, California, last week is connected to the shooters' family by marriage, state documents show.
Mr Enrique Marquez, whose home was raided over the weekend and who is being questioned by federal investigators, was married last year to Ms Mariya Chernykh, whose sister is the wife of Mr Raheel Farook, brother of one of the shooters, Syed Rizwan Farook.
The family connection, revealed in marriage documents seen by Reuters, adds another element to the relationship between Farook and Mr Marquez.
The authorities have said Farook, 28, and wife Tashfeen Malik, 29, were radicalised Muslims who committed an "act of terrorism" when they massacred 14 people on Dec 2.
Farook, the United States-born son of Pakistani immigrants, and Malik, who was born in Pakistan and spent much of her life in Saudi Arabia, died in a shootout with police several hours after the attack in San Bernardino, about 100km east of Los Angeles.
Two assault-style rifles used in the attack were legally purchased by Mr Marquez, who has been described by several of his neighbours as having been a good friend of Farook, according to the US Bureau of Alcohol, Tobacco, Firearms and Explosives.
The Farook brothers lived next door to Mr Marquez when they were growing up.
Mr Raheel Farook, the older brother and who became the brother-in-law of Mr Marquez, served in the US Navy, joining in 2003 shortly after graduating from high school.
Federal agents raided the Mr Marquez home in Riverside, California, on Saturday. Mr Marquez was being interviewed on Tuesday, a law enforcement official said. He had checked himself into a Los Angeles-area psychiatric facility following the shooting.
The marriage documents show that Mr Marquez married Ms Chernykh on Nov 29, 2014. It could not be determined whether they currently live together.
Witnesses to the marriage were Ms Chernykh's sister, Tatiana Farook, and Tatiana's husband Raheel Farook, the shooter's brother.
Mr Farook married Tatiana, then known as Tatiana Gigliotti, on Sept 10, 2011, the documents show.