Photo by Matt Cohen.

At an FBI press conference earlier today, Valerie Parlave, assistant director of the Washington field office, provided the latest information on Aaron Alexis’ alleged shooting spree at the Navy Yard, which resulted in twelve people being killed and three injured.

“We believe at this time that the deceased shooter, Aaron Alexis, acted alone,” Parlave told the press, “And with no other suspects at large, the investigation has moved into a phase of evidence recovery and information gathering.” Parlave said forensics teams are collecting evidence at Navy Yard, and the investigation is collecting as much background information as possible to help paint a better picture of what led Alexis to allegedly go on his shooting spree. At this time, there’s no official leads or theories about a motive that Parlave would comment on. Parlave said it could take “weeks or months” before they could learn more.

What we did learn from Parlave’s briefing is that Alexis entered Building 197 at the Washington Navy Yard with “legitimate access…as a result of his work as a contractor,” and that he “utilized a valid pass to gain entry into the building.” Parlave also commented on the misinformation floating around the media over the past day, particularly in regards to the alleged AR-15 semi-automatic rifle Alexis used, and cleared up by saying that he used a shotgun obtained legally in Virginia and possibly a handgun that he picked up after he entered the building. Parlave confirmed that Alexis did not use an AR-15.

Finally, Parlave shared what the FBI has learned about the days leading up to yesterday’s shootings, saying “Alexis arrived in the Washington, D.C. area on or about August 25th.” According to Parlave, “he has stayed at local hotels in the area since that time,” but most recently, the FBI learned that he had been staying at a residence in Southwest D.C. since September 7, and they’re looking into that.

“We’ve received hundreds of tips that we’ll continue to follow up on,” Parlave said. Parlave also said that the investigation isn’t only taking place in D.C., but also the various other cities where Alexis spent some time. “We’ll continue to run down every lead we can to determine a motive.”

Also on hand at the press conference was Metropolitan Police Department Chief Cathy Lanier, who gave a brief update of the officer who was shot, saying that he’s in good health and is “confident” he’ll make a full recovery.

Lanier praised the “heroism” of all the officers who responded to yesterday’s shooting, calling their handling of the situation heroic. “I have seen things that we have trained for and planned for for years come into place nearly flawlessly,” Lanier said. “There’s no doubt in my mind they saved numerous lives by engaging the way they did.”