The core values of FBI were lost in the J. Edgar Hoover years when its mission was set aside to attack the enemies of the current administration, Democrat or Republican, Liberal or Conservatove.
Since then, its been a secret police to the bitter end.
Those core values were always about as important as Jesus' Beatitudes are today, which is to say, propaganda for the idealist novice.
Agreed, to the bottom-rung investigators (which includes all the non-agent, non-administrative specialists who, I believe, outnumber the special agents) they're there to investigate.
And according to Glenn Kirchner, the political leaning is a big regret and big resentment of the investigative staff. And yet, it's shadow looms over them, as they pressured on issues like going dark seeking less information security and more surveillance powers, that allow for the authoritarian monolith we face today.
If they focused a bit more on seeing justice done and finding the truth through forensic science rather than getting the bad guy by any means including mass surveillance (and neutering fourth-amendment protections of civilians) then we'd be better protected from the autocratic coup / kleptocracy that has a stranglehold on the federal government.
The FBI’s core values, including integrity, compassion, fairness, and allegiance to the Constitution - and oh, yeah, diversity, are being painted over at the FBI Academy. Source: NYT.