Matthew Brown is an American former national-security worker whose public relevance comes from his self-attributed authorship of the disputed Immaculate Constellation report. Brown says he worked in and around the U.S. national-security enterprise, encountered UAP-related material on government systems, wrote an unclassified report from nonpublic sources, and later identified himself as the person behind the anonymous Immaculate Constellation memo that entered the House record in November 2024.1234
The Self-Reported National Security Path
Brown writes that he was born in 1991 in southern California, graduated high school in 2009, attended community college, and moved to Washington, D.C. in 2015 to pursue intelligence work.1 He says his first national-security job was as a Department of Defense contractor working against weapons-of-mass-destruction proliferation, and that his daily work location was the Pentagon.1
His own account places his first direct UAP exposure in 2018, when he says recently activated clearances put him in a position to review military and intelligence videos, reports, telemetry, and other encounter data.1 He later wrote that archive duty led him to what became known publicly as the Immaculate Constellation briefing, which he characterized as a leadership-level overview of a global UAP intelligence-collection mission.1
From Internal Claim to House Hearing
The allegation entered public view before Brown did. On October 8, 2024, Michael Shellenberger published a Public article saying a current or former U.S. government official had written a report alleging an active, secretive UAP-focused special access program called Immaculate Constellation.5 Shellenberger's article did not name Brown.
The House committee repository for the November 13, 2024 joint hearing lists Shellenberger as a witness and includes a support document titled "UC - Mace - Report - Immaculate Constellation - Pentagon."4 In the hearing transcript, Nancy Mace said the document Shellenberger brought would be entered into the congressional record, described it as 12 pages about an unacknowledged special access program, and later entered it without objection.6
Shellenberger's written testimony repeated the report's core allegations: that a UAP whistleblower claimed Immaculate Constellation was created after the 2017 AATIP publicity, served as a central or parent USAP, and consolidated UAP observations from tasked and untasked collection platforms.7 The same testimony also recorded the Department of Defense denial that it had any present or historical record of a SAP by that name.7 During questioning, Representative Clay Higgins noted that the report carried no author's name; Shellenberger answered that he was not its author.6
Brown Goes Public Through Weaponized
Corbell and Knapp's Weaponized series supplied the public self-attribution. Episode 74, published April 29, 2025, said the previously anonymous source of the Immaculate Constellation report was ready to identify himself and explain where he worked, how he first encountered the term, and why he chose to come forward.8 Episode 75 described Brown as a former Defense and State Department analyst and said he had tried to report what he learned about an unacknowledged special access program before going public.9 Episode 76 stated directly that Brown authored the Immaculate Constellation report submitted to Congress and said his account was based on evidence uncovered during his national-security work.10
Brown's later first-person chronology broadly matches that release path while adding claims that remain dependent on his account. He says that after David Grusch went public and the July 26, 2023 UAP hearing occurred, he met Senate Select Committee on Intelligence staff on August 17, 2023 and used his real name.2 He says he later prepared the Immaculate Constellation report, provided a classified version to State Department leadership, and received Department of State approval for public release in summer 2024 with no redactions.2 He also says he met Shellenberger in California, arranged anonymity for the October 2024 article, and worked with Corbell shortly before the hearing to finalize the public document for Congress.2
Evidence Claims and Official Counter-Record
The House record shows that the Immaculate Constellation support document was posted and discussed at the hearing, but does not establish that the alleged program exists, that Brown had the access he describes, or that the imagery and sensor examples in the report are authentic.4611
A one-page ODNI FOIA release approved on November 6, 2024 summarized the press allegation as a supposed unacknowledged UAP special access program, noted that the journalist's source allegedly came across the material accidentally and wrote a report for Congress, and recorded Sue Gough's DoD denial that Immaculate Constellation existed or that DoD had evidence for it.12
AARO's March 2024 Historical Record Report said it found no evidence that a U.S. government investigation, official review panel, or academic-sponsored research had confirmed a UAP sighting as extraterrestrial technology, and it assessed named or described hidden UAP reverse-engineering programs as nonexistent, misidentified sensitive programs, or disestablished efforts lacking merit.13
John Greenewald reported in January 2026 that a Black Vault FOIA request for emails to or from Maj. Gen. Derek O'Malley containing "Immaculate Constellation" produced no search because the Office of the Secretary of War/Joint Staff said the subject matter did not exist; the same article contrasted that with an earlier NSA Glomar response that neither confirmed nor denied responsive records.14
After Going Public
Brown's own September 2025 assessment was that he was unemployed, unprotected, and approved only to speak about the Immaculate Constellation report, while anything beyond it would require further executive approval or congressional protection.3 Weaponized later described him as seated with Corbell at the September 2025 UAP hearing cycle and again called him the author of the document shared with Congress.15