The FBI this afternoon released chilling new video of Aaron Alexis inside the Washington Navy Yard building where 12 people were killed.
The surveillance video shows Alexis' vehicle coming into a Navy Yard parking garage, and then him entering the Naval Sea Systems Command headquarters with what appears to be a duffel bag.
Alexis is then seen walking through the building, armed with a shotgun.
The FBI says there is no indication that the man targeted any specific individuals when he opened fire inside a building, killing 12 people.
Valerie Parlave, head of the FBI's field office in Washington, said Wednesday during a news conference that investigators are continuing to explore the background and motivations of the 34-year-old Alexis. However, she says Alexis had a well-documented history of mental health issues.
Parlave says Alexis held a delusional belief that he was being controlled by extremely low frequency waves, or ELF waves. Alexis had written "my ELF weapon" on a shotgun he used in the rampage.
Alexis, a former Navy reservist and IT contractor, was killed in a shootout with police.