“Bobby Kennedy for President,” a four-part documentary coming out shortly before the 50th anniversary of Robert F. Kennedy’s assassination, sounds like a departure for Netflix. The streaming service’s lineup of original documentary series has been dominated by variations on true crime, with the occasional side trip into environmental scandal or cooking. A comprehensive survey of a major historical figure would be something new.

So maybe it’s not surprising that the series, directed by Dawn Porter (“Trapped,” “Spies of Mississippi”), is an odd hybrid — a conventional, public-television-style biographical documentary that veers, in its fourth hour, into the sort of true-crime investigation Netflix is known for. Then at the last minute it swerves again, with a jarringly sentimental reunion and visit to the scene of the killing that’s straight out of the feel-good branch of reality TV.

Throughout, “Bobby Kennedy for President” provides information and sometimes fascinating film clips without ever giving us much of a sense of its subject, who remains a Don Draper-like cipher. Outside of the third hour, which covers the 1968 presidential campaign, he’s a supporting player in the dramas of other people: his brother John, Joseph McCarthy, George Wallace, Martin Luther King Jr., Lyndon Johnson. The series often looks like a general social and political history of the 1960s that’s only loosely tied to Kennedy.

The Kennedy of “Bobby Kennedy for President” is a smart, ambitious politician, perhaps more principled than most — it’s hard to judge the depth of his convictions — who managed to capture the imaginations of young Americans and the loyalty of minority voters.