(reviewed at the Gasparilla Film Festival)

Stars Michael Shannon, Chris Evans, Ray Liotta, Winona Ryder, Robert Davi, David Schwimmer. Directed by Ariel Vromen. Written by Vromen and Morgan Land; adapted from Anthony Bruno’s book and Jim Thebaut’s documentary. 103 minutes. Rated R. Critic’s grade: B+

Quick, name a somewhat under-the-radar actor in Hollywood, a superbly skilled actor who seems to have been biding his time in secondary roles or generally underappreciated features until he could sink his acting chops into a juicy role in a high-profile film.

If Michael Shannon, who’s recently gained acclaim as Prohibition agent Nelson Van Alden in HBO’s “Boardwalk Empire” and has a small role in the just-released “Mud” doesn’t come to mind, well, he should.

Shannon, a kick as a bizarrely out-of-control NYPD detective in last year’s high-energy “Premium Rush” and frighteningly convincing as a Midwesterner with disturbing apocalyptic visions in “Take Shelter” (2011), plays a complex character of an entirely different species in “The Iceman.”

The film, based on true events, stars Shannon as Richard Kuklinski, the real-life New Jersey contract killer who confessed to killing 100 people and may have killed even more during the two decades preceding his 1986 arrest.

Let’s get this out of the way right up front: Shannon goes the distance in “The Iceman,” giving a chilling, expertly controlled performance. He perfectly embodies a man with a cold, cold heart and, seemingly, a split personality — Kuklinski is simultaneously a loving family man and a killing machine, perfectly content to make his living by carrying out the bloody orders of his crime-gang overseers.

Israeli-born director Ariel Vromen, who previously helmed the little-seen dramas “Danica” and “Rx,” opens his film with documentary-style footage of the killer, looking like the Unabomber and being subjected to a jailhouse interview. “Mr. Kuklinski, do you have any regrets for the things you did?” the interviewer asks.

Then it’s on to several early scenes that wouldn’t be out of place in a romantic comedy. In particular, there’s a warm and funny sequence at a cozy diner, as Polish-American guy Kuklinski enjoys a first-date with Deborah (Winona Ryder). She’ a nice Catholic girl from the neighborhood, a pretty brunette woman, who isn’t immune to the charms of the tall, quiet, unpretentious guy with the imposing brow. “I dub cartoons for Disney,” he says when asked about his work. It’s not a truthful answer; at the time, he makes his living bootlegging pornographic movies.

Shortly later comes the flip side of that mostly silent, almost sweet guy: At a pool hall, Kuklinski is insulted. He controls his rage, but, as suggested by a near-scowl on his face, the chapter is far from finished. Later, he takes his terrible revenge.

Soon enough, Kuklinski falls in with an employer, local independent gangster Roy Demeo (Ray Liotta), who tasks the passionless murderer with cleaning up a variety of messy situations — “deal with whatever we can’t, for whatever reason.” The hits grow increasingly more grisly. At one point, Kuklinski and a longhaired, ice cream truck driver played by a practically unrecognizable Chris Evans cover their murderous tracks by freezing their victims. The uniformly excellent cast also includes David Schwimmer (with a ’70s adult-movie moustache), playing against type as one of Demeo’s criminal associates, and James Franco and Stephen Dorff in tiny roles that amount to cameos.

Meanwhile, Kuklinski and Deborah marry, and raise two girls, and for the longest time — decades — the hit man is successfully able to keep his worlds from his colliding, and his pent-up rage from exploding. He takes the kids to school and church activities, and tells his wife that their hefty income comes from his work as a currency trader. She buys, or at least pretends to believe, that fiction.

Vromen goes where other directors, including Scorsese and, to some extent, Coppola, have gone before, juxtaposing violent acts with scenes of happy family gatherings, and showing the cumulative moral impact of the evil that these men do. The double-life aspects of “The Icemen,” though, represent something of a twist on the usual gangland fare. And the filmmaker elicits from Shannon a performance that’s absolutely frightening in his portrayal of a guy whose quiet, seemingly shy demeanor belies his true nature — he’s a frightening violent wolf in sheep’s clothing. Even days or weeks after watching Shannon as Kuklinski, it’s hard not to shiver at the memory of it all.