On multiple Fraternal Order of Police websites, they state that Robert F. Kennedy was opposed to Police Review boards and called them a "sinister movement against law enforcement" as described below on the Idaho FOP website for example:
During the 1960s the FOP opposed the creation of police review boards, spearheaded by Robert F. Kennedy, at one point describing them as a "sinister movement against law enforcement". The FOP also clashed with the ACLU on the issue of police brutality, seeing it as a "liberal attempt to discredit law enforcement". The Order was "heartened by Richard Nixon's emphasis on law and order", though it remained strictly apolitical.
The only reference I could find for this quote was a small blurb about a book by Alvin J. Schmidt, who has some...interesting beliefs to say the least and therefore quite biased. Therefore I looked for other sources that corroborates this. The closest thing I found was that Robert F. Kennedy cited a poll by the John Kraft society that people wanted "more police protection" but this is a far cry away from opposing civilian review boards:
The John Kraft organization has conducted a number of polls in Negro and Puerto Rican neighborhoods in New York City, in which it asked people to list their problems. Crime came out "at the head of the list". What the people want, the Kraft group concludes, is "more police protection". And the Kraft report continues: "Problems of 'police brutality'-in all these surveys-are conspicuous by their absence". What people want is more police presence rather than less.
Given that the source for this quote is very biased at best, is there a more reputable source that confirms Robert F. Kennedy's opposition to police review boards in the 1960's?