The Iceman, Venice Film Festival

Michael Caine once explained that the secret of screen acting was to "be like a duck… remain calm on the surface but paddle like hell underneath".

This is advice that the brilliant American actor Michael Shannon has clearly taken to heart. Shannon gives a bravura performance as the real-life mob hitman and New Jersey family man Richard Kuklinski in The Iceman (screening out of competition in the Venice Film Festival).

At work, Kuklinski is impassive and seemingly cold. When a gun is pointed at him or he is preparing his lastest murder (he is thought to have killed well over 100 people), he betrays no emotion whatsoever. Nonetheless, we're always aware of the intense emotions he is suppressing: his anger, his love of his wife (Winona Ryder), his devotion to his two daughters and even a surprising tenderness in him.

The Iceman is a slickly made and very violent thriller. There is more than a touch of Goodfellas about it. Like Martin Scorsese's film, it offers a deglamorised and very detailed picture of mobster life. The presence of Ray Liotta as the utterly ruthless crime boss Roy DeMeo, who takes Kuklinski under his wing, reinforces the sense that we are back in Scorsese's world.

At the same time that Kuklinski is killing anyone who crosses DeMeo, he is leading a middle-class family life with his devoted wife, Deborah. She thinks that he began his career printing cartoon films. In fact, he was shipping porno movies. She is convinced that he is now working as a foreign-currency trader. In fact, his profession is murder.

There are moments of humour as Kuklinski desperately tries to keep up his façade as middle-class father, even as violence swirls around him. He compartmentalises his life and is somehow able to take his daughters roller-skating one moment and commit a contract killing the next.

On the face of it, The Iceman is genre fare. We've all seen mobster movies like this before. But Shannon's brilliance gives the film a surprising, new dimension. He makes us root for a serial killer and even manages to give him a tragic grandeur. Ryder is touching and credible as the wife who somehow hasn't noticed her husband's grisly day job. There are some very colourful character turns, too, from Chris Evans as a fellow killer who drives an ice-cream van and Stephen Dorff as his brother.

However, this is Shannon's movie and underlines his status as arguably the most exciting US screen actor since Pacino and De Niro were in their heyday. He is likely to be in the running for Oscars and Golden Globes... just as long as voters aren't put off by how repulsive The Iceman's crimes are.