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The mother of the Washington Navy Yard gunman said Wednesday she was heartbroken and apologized to relatives of the 12 victims, but added she was glad Aaron Alexis is “in a place” where he can no longer harm anyone.

Cathleen Alexis read a brief statement to reporters at her home in Brooklyn, N.Y. She took no questions.

“His actions have had a profound and everlasting effect on the families of the victims,” Cathleen Alexis said. “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.”

Alexis’ mother added she was “so, so very sorry” for relatives of the 12 victims killed during the gunman’s rampage early Monday at the Navy Yard before he died in a shootout with police.

“To the families of the victims, I am so, so very sorry that this has happened,” she said. “My heart is broken.”

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A Rhode Island police sergeant reported Alexis to naval station police last month after the suspect told cops he was “hearing voices” through his hotel room wall and that three people were following him and sending vibrations into his body, according to a police report obtained by FoxNews.com.

According to the document, the officer said he was sent to a local hotel on Aug. 7 to check out a suspicious person report involving Alexis, who told him he was a naval contractor and travelled often.

Alexis told the officer that while flying from Virginia to Rhode Island, he got into an argument with someone else at the airport who he believed had sent three people to follow him and keep him awake by talking to him and sending vibrations into his body, the report stated.

Alexis also said he thought he heard these three people speaking to him through a wall of his hotel room and through the walls, floors and ceiling of a hotel on the Navy base. Alexis told the officer the trio was using “some sort of microwave machine” to keep him awake.

Alexis, 34, was discharged from the Navy two years ago after serving hitches in Texas and Illinois. He was reportedly armed with a shotgun and two handguns. Alexis sprayed bullets from the fourth floor down to the cafeteria area in the Naval Sea Systems Command headquarters in southeast Washington.

While some neighbors and acquaintances have described him as "nice," Alexis’ father once told detectives in Seattle that his son had anger management problems related to post-traumatic stress brought on by the terrorist attacks of Sept. 11, 2001. He also complained about the Navy and being a victim of discrimination.

The former Navy reservist had a string of misconduct problems during his nearly three years in the military, but he received an honorable discharge.

The officials say Alexis had bouts of insubordination, disorderly conduct and was sometimes absent from work without authorization. The offenses occurred mainly when he was serving in Fort Worth, Texas, from 2008-2011, and were enough to prompt Navy officials to grant him an early discharge through a special program for enlisted personnel.

Officials said the bad conduct was enough to make it clear Alexis would not be a good sailor, but not enough to warrant a general or less-than-honorable discharge.

The Associated Press contributed to this report.