The mother of Aaron Alexis, the Washington Navy Yard shooter, said Wednesday that she was heartbroken and sorry for the families of the victims and that she was glad he is "in a place where he can no longer do harm to anyone."
In a brief statement to a reporter in New York, the woman, Cathleen Alexis, said her son "has murdered 12 people and wounded several others."
"His actions have had a profound and everlasting effect on the families of the victims," she said, her voice trembling. "I don't know why he did what he did, and I'll never be able to ask him why. Aaron is now in a place where he can no longer do harm to anyone, and for that I am glad."
She added: "To the families of the victims, I am so, so very sorry that this has happened. My heart is broken."
She took no questions after the statement.
Earlier in the day, a woman whom Aaron Alexis stayed with in Thailand last year said that he was crazy "in a positive way, like funny," and that she was shocked to learn that he had carried out the massacre at the Navy Yard. The spree ended when Alexis was gunned down by officers.
The woman, Om Suthamtewakul, is the sister of a former roommate of Alexis' in the U.S. She told NBC News in an interview that Alexis stayed with her for a month and a half and showed no sign of anger.
"So I can't really believe how he can shoot those people," she said in Thai. "He looked kind of like, you know, bonkers, crazy, in a positive way, like funny, but, so I really can't believe this."
Suthamtewakul said Alexis liked her country, "loved Thai woman" and wanted to go back. She said that she and Alexis went on outings in Bangkok and elsewhere and that they went to massage parlors in the evening.
She said she never saw him show cruelty.
"Every day he has good mood, laughing," she said, "and one time we went to the market together because he understand Thai and he heard one Thai woman saying rude words about him — but he didn't get angry, he laughed and told the woman, 'I understand what you said.'"
President Barack Obama plans to attend a memorial service for the Navy Yard victims Sunday, the White House press secretary said. Two days after the shooting, Navy Yard employees were told by text and email that they could retrieve their cars from the base, which the commander said would be back at full operation Thursday.
'Why' remains unanswered
Authorities say they are still looking for a motive. Since Alexis carried out the attack Monday at the headquarters of the Naval Sea Systems Command, signs have emerged of a troubled history.
• Alexis, who served as a naval reservist from 2007 to 2011 and worked more recently as a civilian contractor, had a military disciplinary record that included disorderly conduct, insubordination and unexcused absences.
Newport, R.I., police said he called them Aug. 7 to say he had changed hotels twice because he believed people were chasing him and sending vibrations through the walls to keep him from sleeping.
Police said they had forwarded their report to police at the naval station in Newport. Military officials told NBC News on Wednesday that they had found no evidence that naval police forwarded the information to any higher command outside the base.
• The Department of Veterans Affairs said Wednesday that it saw Alexis twice. He went to a VA emergency room in Providence, R.I., on Aug. 23 complaining of insomnia and was given sleep medicine and told to follow up with a doctor, the agency said. Five days later, Alexis showed up at a VA emergency room in Washington to get a refill and was again encouraged to see a doctor, the VA said.
The VA said Alexis denied struggling with anxiety or depression or having thoughts about hurting himself or others. It also said he enrolled in VA health care in February 2011 and never sought an appointment for mental health.
• Alexis also had run-ins with the law over gun violence. He was accused in 2004 of having shot out the tires of a car in Seattle and in 2010 of having fired a gun into an upstairs apartment in Fort Worth, Texas.
• Friends and relatives have also said he had a preoccupation with the Sept. 11, 2001, attacks, felt slighted as a veteran, had money problems and was so unhappy with his life that he considered leaving the U.S.
Law enforcement officials told NBC News that Alexis created a webpage with the name "Mohammed Salem," but they said he never did anything with it. They said they had found nothing else that might indicate any interest in violent jihad or even in Islam.
Defense Secretary Chuck Hagel said Wednesday that "obviously there were a lot of red flags" in Alexis' past, including the Rhode Island police report that was passed on to the Navy, and that the department would look into why they were not picked up.
No specific target uncovered
According to the latest account put together by investigators, Alexis left a Residence Inn in Washington on Monday morning, drove a rental car to the Navy Yard and used his credentials to enter the base. Military officials said Alexis had a security card that allowed him access to the Navy Yard but not to the office building where he later opened fire.
Alexis went into a fourth-floor bathroom carrying a bag, took out a shotgun, went to a fourth-floor balcony and began firing into an atrium below.
He then went to the first floor, shot a security guard and took his handgun, and went back upstairs to resume the rampage, investigators say. Most of Alexis' victims were hit with shotgun blasts, but others were hit by bullets from the handgun.
A survivor of the rampage was released from the hospital Tuesday after having been shot in her head and hand. Two other Navy Yard victims at the same hospital have been upgraded to good condition from fair, the hospital said Wednesday. Those are a D.C. police officer who was shot in the leg and a woman who was shot in the shoulder.
Criminal profilers say mass shootings often begin with a single target in mind, but investigators have not identified any such prime target for Alexis.
Authorities said Alexis used a Remington shotgun to shoot the security guard and a police officer before taking one of their handguns and continuing his rampage. He had scratched two phrases into the shotgun:
"Better off this way"
"My ELF weapon"
Authorities said they were at a loss as to what the second phrase might mean.
Less than two days before his shooting spree, Alexis rented an AR-15 semi-automatic rifle and used it for target practice at a Northern Virginia gun range and store. Some earlier reports said he had used an AR-15 in the shootings, but the FBI said Tuesday that it did not believe he did.
J. Michael Slocum, a lawyer for Sharpshooters Small Arms Range in Lorton, Va., said in an email to NBC News that Alexis bought a Remington 870 shotgun and about 24 shells of ammunition Saturday. Alexis listed his residence as Texas.
Slocum said he had no information on whether Alexis sought to buy an AR-15 at Sharpshooters. Alexis bought the shotgun legally, D.C. Police Chief Cathy Lanier said.
Obama on Tuesday ordered a review of government contractor and employee security across federal agencies. Asked about new gun-control measures in the wake of recent shooting sprees, Obama lamented what he said was Congress' inability to take action.
"The fact that we do not have a firm enough background-check system is something that makes us more vulnerable to these kinds of mass shootings," Obama said in an interview with Telemundo. He added that "ultimately this is something that Congress is going to have to act on."
Jeff Black, Tracy Connor, Jason Cumming, Jonathan Dienst, Richard Esposito, Courtney Kube, Charles Hadlock, Peter Jeary, Jim Miklaszewski, Andrew Rafferty and Ali Weinberg of NBC News contributed to this report.