The First Criminal Charges in the San Bernardino Shooting

Federal prosecutors arrested on Thursday a friend of one of the San Bernardino shooters who investigators say purchased assault weapons that were used in the deadly attack this month.

The FBI arrested Enrique Marquez, 24, a longtime friend and former neighbor of Syed Rizwan Farook, the man who, along with his wife, Tashfeen Malik, killed 14 people and wounded 21 others in a shooting rampage at his office holiday party in California earlier this month, the Associated Press and several other news organizations reported.

Marquez has been charged with providing material support for crimes of terrorism, conspiring with Farook to commit terrorist attacks in 2011 and 2012 that were never carried out, and other crimes. Prosecutors say Farook radicalized Marquez, who converted to Islam, according to The New York Times. Authorities believe Marquez purchased two assault rifles as a favor to Farook, who would then not have to go on record as the buyer and undergo a background check, according to NBC News.

Marquez, who was not directly involved in the San Bernardino shooting, is the first person to be charged in connection with the assault.

Federal officials determined soon after the attack the shooters were inspired by foreign terrorist organizations. The Islamic State praised the assault, calling Farook and Malik “followers,” but did not claim responsibility for organizing it, as it had done in Paris last month.

In the days after the shooting, one question emerged: Did U.S. intelligence miss warning signs about Farook and Malik. Farook was born in Illinois and had worked for the San Bernardino County’s public health department as an inspector for five years. Malik was born in Pakistan and arrived in the U.S. last year on a fiancee visa to marry Farook, whom she’d met on a dating website for Muslims. The couple had a six-month-old child, and lived in a quiet neighborhood not far from where the shooting occurred.

But while Farook and Malik had spoken of jihad online several years ago, even before they began dating, “those communications are private direct messages,” said the FBI’s director, James Comey, on Wednesday. The messages were also general in nature, and not about specific plots. Comey’s remarks appeared to refute news reports that Malik had pledged allegiance to the Islamic State in a public Facebook post the morning of the assault, which Facebook had reportedly confirmed. As my colleague David Graham wrote Thursday, “the fact that the messages in question were private, beyond the reasonable ken of law enforcement and well past constitutional limitations, is yet another indication of the steep challenge American officials face in trying to stop homegrown attackers who are inspired by ISIS or other terrorist groups but appear to be acting largely autonomously, without instruction from known terrorist leaders.”

President Obama recently pointed to the difficulty of uncovering and preventing homegrown jihadist terrorist plots. “As groups like ISIL grew stronger amidst the chaos of war in Iraq and then Syria, and as the Internet erases the distance between countries, we see growing efforts by terrorists to poison the minds of people like the Boston Marathon bombers and the San Bernardino killers,” he said.

Funerals for the shooting victims were held this week. Obama will travel to San Bernardino on Friday to meet privately with the families of the victims.