"In regards to the weapons used by Mr. Alexis, there has been a lot of information circulating in the media over the past day," Parlave said. "Once again, we caution against obtaining information from unofficial sources, and we ask that all inquiries be directed to the FBI. At this time, we believe that Mr. Alexis entered Building 197 at the Navy Yard with a shotgun. We do not have any information at this time that he had an AR-15 in his possession. We also believe Mr. Alexis may have gained access to a handgun once inside the facility and after he began shooting."
Parlave's account is the most official word we have so far about the weapons used by Alexis on Monday. And it all but rules out a version of events that had spread widely after the shooting. Major news outlets (here's a good list) reported on Monday that Alexis used an AR-15. The New York Daily News went all out, putting the weapon on its cover on Tuesday, as a way of tying Monday's incident to December's shooting in Newtown, Conn. Headline: "Same Gun Different Slay." But it now appears that the Daily News, along with many others, got it wrong.
The Daily News' coverage is an example of why this matters. Semi-automatic rifles, like the Bushmaster model carried by Newtown shooter Adam Lanza, and high-capacity magazines became a major part of the gun control policy debate in the aftermath of that shooting. If Alexis had used a similar weapon on Monday, the Daily News' cover on Tuesday would have been just the start of a renewed round of news coverage. (Before the FBI came forward to correct the record, Sen. Dianne Feinstein (D-CA) had already weighed in.)
So if Alexis didn't use an AR-15 on Monday, how did that assertion enter the news coverage? A few explanation have been offered so far -- and even those seem to conflict.
Tuesday afternoon, NBC News reporter Pete Williams -- who earlier in the day had spoken on-air about "the AR-15 semiautomatic assault-type rifle and a handgun, which [Alexis] apparently took from a law enforcement officer that he wounded" -- appeared on MSNBC and offered a preview of the FBI's current account of the weapons used.
"Today law enforcement people are saying their assessment now is that he had only the shotgun and two handguns that he did the shooting with," Williams said. "So we don't know, we think what happened is that as an AR-15 was found near his body when he was discovered to have been killed and they assumed he had had that. Perhaps some witnesses thought that they say him firing that, but they now say just the two handguns and the shotgun."
CNN, meanwhile, has offered a different explanation. An anonymous U.S. law enforcement official told the network on Monday that Alexis had used an AR-15. By Tuesday, the network was citing "federal law enforcement sources" to walk back that assertion.
"The sources, who have detailed knowledge of the investigation, cautioned that initial information that an AR-15 was used in the shootings may have been incorrect," CNN reported. "It is believed that Alexis had rented an AR-15, but returned it before Monday morning's shootings."
It's a cliche, but the real answer might be the one that applies so often to the early reporting about mass shootings: the truth takes time to pin down.