|Not a CIA officer|
2. Enlisted information from at least a half-dozen other intelligence agency operatives with key White House access.
3. He/she writes well and clearly.
4. Delivered his report on August 12 to the Inspector General of the "intelligence community."
5. He knew about Trump's call to Ukrainian President Zelensky. He knew its content. He knew it had been hidden in a computer server reserved for the highest top secret counter-intelligence information. He had never seen the "call notes," yet his knowledge of their content and their import was eerily accurate.
6. The whistleblower initially submitted his concerns anonymously -- and not in official whistleblower form, not yet -- to the general counsel at the CIA, Courtney Simmons Elwood.
6a. Elwood shared the anonymous communication from the whistleblower with John A. Eisenberg, a deputy White House counsel, who "was already aware of vague concerns about the call [between Trump and Zelensky]."
6b. Together, Elwood and Eisenberg determined that "the accusations had a reasonable basis," and they together took them to John Demers, the head of the Justice Department’s national security division.
6c. Demers went immediately to the White House to read the transcript of the call and assess whether to alert other senior law enforcement officials. He then looped in the deputy attorney general, Jeffrey A. Rosen, and Brian A. Benczkowski, the head of the department’s criminal division.7. Meanwhile, the whistleblower was growing concerned that CIA General Counsel Elwood was not taking him seriously. He learned that she had gone to the White House with his complaint. So he doubled down, went through channels prescribed by law for official whistleblower complaints -- and we're barely more than a month into this unraveling.
8. At the end of August, the office of the director of national intelligence referred the whistleblower's official complaint to the Justice Department (see John Demers, Jeffrey A. Rosen, and Brian A. Benczkowski -- 6b and 6c above) as a possible criminal matter.
Justice Department ultimately declined to open an investigation.
Note on Sources: I've been reading non-stop for two days, not always marking my path, but today it's the team of Julian E. Barnes, Michael S. Schmidt, Adam Goldman, and Katie Benner, among others. Do some Googling.