Days after the horrific shooting at the Washington Navy Yard, it's a muddy picture emerging of the latest face of terror, Aaron Alexis.
His mother had no answers.
“His actions have had a profound and everlasting effect on the family of the victims,” said Cathleen Alexis. “I don't know why he did what he did, and I will never be able to ask him why. Aaron is now in a place where he can no longer do any harm to anyone, and for that I am glad. To the families of the victims, I am so very sorry that this has happened. My heart is broken."
For profilers, hearing the recollections from those who knew him, it's an all too familiar story.
“In this case, as in other cases, the shooter has a lot of contradictory behavior taking place so you've heard him described as a sweet guy and then you've heard other people describe him as fairly aggressive,” said Mary Ellen O’Toole, a former FBI profiler. “That to me suggests something unpredictable.”
Alexis’ Remington 870 pump action shotgun left a horrific scene of carnage in less than half an hour.
ABC News has learned that Alexis carved the words “BETTER OFF THIS WAY" and “MY E-L-F WEAPON" on the stock of his shotgun.
Investigators are examining the meaning of the phrases, including whether “BETTER OFF THIS WAY” meant Alexis knew he would die in his murderous rampage.
As for E-L-F, authorities haven't figured out what it means, though some investigators wonder if it is an abbreviation for “extremely low frequency,” given his background as a computer technician, and the bizarre story Alexis told police last month about hearing voices and microwave machines bombarding his body.
“These are high-profile mass homicides and in each of them, it's usually in a couple of days, it surfaces that there are mental health issues or mental health conditions,” explained O’Toole.
After hearing those voices, Alexis went to a Veterans Administration hospital complaining of insomnia. Officials gave him sleeping medication. When asked if he had thoughts of hurting anyone or himself, he said no.
“Thinking about it, conceptualizing it, planning it in his head, that probably predated months if not years before the incident,” said O’Toole. “This is not snapping behavior, these crimes are not impulsive acts.”
A dozen blocks away on Capitol Hill, the relatives of victims from previous mass shootings were once again pleading for new gun legislation.
“I don't want another family to go through what I'm going through right now,” said Carlos Soto, brother of Victoria Soto, who was killed in the shooting at Sandy Hook Elementary School. “I don't want another 15-year-old to be having to pick out his sister's casket. I don't want that to happen.”
“What about our children? They have a right to live,” said Sandra Robinson, who son was killed while sitting on his grandmother's porch in Chicago. “We're standing as mothers and fathers up here. It's a constant ache in our heart that we can never get rid of.”
Today, the Naval Yard will reopen, back to business. But the pain of the families of the dead and wounded remain fresh. And once again, questions remain unanswered about how another killer slipped through the cracks.