Federal agents on Thursday arrested Syed Raheel Farook, the brother of one of the two terrorists who carried out a deadly mass shooting in San Bernardino last December, as well as two others, the Los Angeles Times reported. Syed Rizwan Farook and his wife, Tashfeen Malik, went on a rampage late last year at the Inland Regional Center in the California city.

Speaking on condition of anonymity, a law enforcement official told the L.A. Times the arrests in Corona, California, were not directly related to the investigation of the attacks that left 14 people dead.

Mariya Chernykh, 26, and Tatiana Farook, 31, also were arrested, KABC-TV in Los Angeles reported. Chernykh’s husband, Enrique Marquez Jr., was charged in December with multiple counts, including alleged conspiracy with the gunman Rizwan Farook. The latest arrests came following a search of Raheel Farook’s home. It was conducted pursuant to the third search warrant issued since the mass shooting.

The arrests reportedly were related in part to alleged false statements and marriage fraud.

After the mass shooting, people who knew the brothers said their personalities starkly contrasted. They indicated the older Raheel Farook was considered comparatively extroverted, while the younger Rizwan Farook was considered comparatively introverted.

Raheel Farook served in the U.S. Navy between 2003 and 2007. He was awarded both the Global War on Terrorism Service Medal and the Global War on Terrorism Expeditionary Medal. He served for three years as an information system technician aboard the aircraft carrier USS Enterprise.

The San Bernardino shooting was the deadliest act of terrorism in the U.S. since the Sept. 11, 2001 attacks on America. In addition to the 14 people killed at the Inland Regional Center, at least 22 others were wounded there. The two terrorists were killed hours after the attack during a shootout with police.

Family members came out quickly after the attack to express their condemnation of it.

“I have no idea why he would do that,” said Farhan Khan, a brother-in-law. “The reason I am here is to express [for] my family ... how sad they are for what happened. ... I’m very sad people lost their lives and there are victims out there,” he said.