WASHINGTON — Before arranging a meeting with a Kremlin-connected Russian lawyer he believed would offer him compromising information about Hillary Clinton, Donald Trump Jr. was informed in an email that the material was part of a Russian government effort to aid his father’s candidacy, according to three people with knowledge of the email.
These people aren't really identified here, but previously three people (likely the same) were identified as "advisers to the White House." That's a bit ambiguous, but not so broad as to include the entire universe of people.