Entertainment

SETH ROGEN’S GOT MALLS!

SETH Rogen, a consistently genial stoner presence in what seems like every fourth movie these days, shows he can actually act in “Observe and Report,” a disturbingly humorous cross between “Paul Blart: Mall Cop” and “Taxi Driver.”

While not the laugh riot some of my critical colleagues have been recklessly promising, this second feature from Jody Hill (“The Foot Fist Way”) is admirable for venturing into very dark places rarely glimpsed in big-studio comedies — thanks, Warner Bros.! — like (gulp) date rape.

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“Part of me thinks this disgusting pervert is the best thing that ever happened to me,” announces Rogen’s Ronnie after a schlubby flasher begins terrorizing the low-rent Middle American mall where Ronnie is somehow director of security.

The sick joke is that the flabby, sociopathic Ronnie is neither physically nor mentally all that far removed from the very naked and modestly endowed flasher (Randy Gambill).

The latter’s appearance inspires an attack of grandiosity in our hero, whose transgressions up to now have been pretty much limited to racially harassing a lotion vendor he calls Saddam and cruelly leading on a temporarily handicapped barista (Collette Wolfe) who has a crush on him.

In short order, Ronnie guiltlessly forces himself on a wasted perfume demonstrator (Anna Faris) freaked out by the flasher, joyfully tosses his medications for bipolar disorder — and declares war on the police detective (Ray Liotta) investigating the flasher case.

Further emboldened by a surprising law-enforcement triumph, the mood-swinging Ronnie applies for a police job — and this deluded bully’s wildly inappropriate interview with a dumbfounded psychologist is perhaps the movie’s comic high point.

It’s possible to sympathize with our junk-food-loving hero — mildly reminiscent of the sick cop played by Michael Rooker in Kevin Smith’s 1995 flop “Mallrats” — to a limited extent.

He’s a product of a toxic environment, spending his nights with a mother (Celia Weston, quite brilliant) who’s a falling-down drunk and spending his days with a lisping, gung-ho lieutenant (Michael Pena, better known for dramas like “World Trade Center”) who is beyond weird.

With a few tweaks, “Observe and Report” could have been turned into a drama.

And indeed, Liotta plays it almost entirely straight in his most effective performance since “Goodfellas.”

He slowly goes from thinking Ronnie is a harmless nuisance to realizing he is something much, much more dangerous.

As the comedy ventures into territory involving serious use of deadly force, you wonder just how far Hill and Rogen — who, unlike many comics, does not hold back on the unpleasantness — are going to push this.

Is the ending a cop-out or welcome restraint? There will be debates about this.

Either way, this is not really a movie for the masses who went to see Rogen in “Knocked Up” — or the wildly and inexplicably popular “Paul Blart: Mall Cop,” for that matter.

I don’t want to oversell it, but “Observe and Report” is the sort of offbeat studio movie that should be encouraged.

lou.lumenick@nypost.com