Gee … you think? Based on the opening of this CBS News report, they may still be missing a few clues. At least according to CBS, the investigators are still puzzling over what motivated Syed Farook and Tashfeen Malik, as well as who.

Come on, man. Three guesses on the what, and the first two don’t count:

As investigators focus on what or who motivated San Bernardino shooters Syed Rizwan Farook and his wife, Tashfeen Malik, to open fire at the Inland Regional Center, a report about Malik’s comments on social media before she moved to the U.S. is raising questions about how thoroughly she was vetted.

Law enforcement sources confirmed to CBS News that Malik made radical postings on Facebook as far back as 2012 — the year before she married Farook and moved to the U.S., reports CBS News correspondent Carter Evans. According to a report in the New York Times, Malik spoke openly on social media about her support for violent jihad and said she wanted to be a part of it. But none of these postings were discovered when Malik applied for a U.S. K-1 fiancé visa.

Soooooo …. that should cover the what, yes? It’s really the how that matters now, as in how five government agencies somehow missed that Malik was openly calling for violent jihad before applying for the K-1 “fiancé” visa that the US eventually granted. In fact, we now know that she was looking to join a jihadist group two years before coming to the US:

“If you’re going to start doing a deeper dive into somebody and looking at their social media postings or other things, you really want to focus your effort on the high-risk traveler, the person that you’re really worried about being a threat to the United States,” said James Carafano, national security expert and vice president of the Kathryn and Shelby Cullom Davis Institute for National Security and Foreign Policy at the Heritage Foundation. “The question is, how do you identify them?”

Malik was not identified as a threat despite being interviewed at the U.S. Embassy in Pakistan and vetted by five different government agencies that checked her name and picture against a terror watch list and ran her fingerprints against two databases.

CBS also covers the search for the terrorists’ missing hard drive. Here’s another educated guess: if the couple went to enough trouble to get rid of their hard drive and smash their smartphones, they clearly wanted to hide something from investigators after their terror attack. Malik posted her allegiance to ISIS on Facebook just before or during the attack, so what else would the couple need to hide? I’d bet money that they wanted to clear up their trail to other conspirators or to members of the kind of group Malik wanted to join in 2012.

With all of this going on, the question will be how Barack Obama and his administration can argue with a straight face that they can vet Syrian refugees en masse to cull out the terrorists. They couldn’t even spot Malik and her social-media declarations with five government agencies from two countries which are nominally stable and friendly to the US.

As to protecting their network, would that include Enrique Marquez? The Washington Post update on Marquez makes it sound as though investigators think he may not have been involved — despite Marquez’ co-conspirator status in Farook’s aborted 2012 attack plans:

According to senior U.S. law enforcement officials, Marquez has told the FBI that he and Farook had discussed mounting some sort of attack in 2012, but then he got spooked after a terrorism investigation based in Riverside resulted in the arrest of four local men in November of that year for plotting to kill Americans in Afghanistan. The men were convicted and sentenced to long prison terms.

Agents are investigating whether those men or any of their associates — or the FBI’s confidential informant in that case — had contact with Farook or Marquez. Lawyers involved in the case said they were unaware of a direct connection.

It is not clear whether Farook and Marquez chose a specific target or time to carry out the attack they had discussed, the officials said. The FBI is investigating whether the rifles that Marquez bought were intended for use in that 2012 attack that was called off, the officials said.

If they were — or if Marquez knew at the time when he transferred the rifles to Farook that they were going to be used for a violent act — he could be charged with a federal felony, according to law enforcement officials. Authorities do not believe that Marquez had any direct knowledge of the later plot by Farook and Malik.

Well, that may be possible, but that should be taken with deep skepticism, especially if Marquez did arrange the straw-man purchases of the rifles used in the attack. Maybe the hard drive would have more information on Marquez’ role. But more to the point, perhaps a more thorough vetting of Malik’s K-1 visa would have made all of this unnecessary in the first place.