(Keith Bernstein/KEITH BERNSTEIN)

With the online arrival of the first trailer for “J. Edgar,” we get our first preview of what Leonardo DiCaprio both looks and sounds like in the role of the powerful and controversial FBI director J. Edgar Hoover.

As much as one can tell from a two-and-a-half minute clip, DiCaprio’s work has potential Oscar nominee written all over it. In the role, the actor ages, he mourns the death of his mother, he asserts his authority as head of the FBI and he covertly pursues a relationship with right-hand man Clyde Tolson, played by Armie Hammer.

In other words, it’s a part that captures a significant historical figure’s entire lifetime and gives DiCaprio plenty of big, dramatic scenes to command — the stuff Academy Award-nominated performances are made of. Naturally, we won’t know for sure if DiCaprio rises to the challenge until the film screens more widely. (It releases Nov. 9.)

But with Clint Eastwood directing and Judi Dench also co-starring as Hoover’s mother, it’s safe to bet that we’ll be hearing about this biopic more and more as awards season accelerates into full, for-your-consideration gear.

Watch the trailer below.