Kathleen Turner seems to be having the time of her life in "Serial Mom," playing Beverly Sutphin, a deranged homemaker who, on the surface at least, seems to be the perfect supermom. In reality, however, Beverly is a serial killer who takes out neighbors, teachers and friends of her children in retaliation for such crimes against humanity as refusing to recycle, driving without a seat belt and chewing gum.

"Serial Mom" is played out in a straight-faced manner most of the way, showing dates and times at the bottom of the screen to evoke that reality TV movie-of-the-week sensation. And writer-director John Waters ("Hairspray," "Polyester") sets his sights on such ripe satirical targets as tabloid television programs (which have been a bit overspoofed lately), courtroom dramas and the idealized, cliche-ridden fantasy view of "Leave It to Beaver" suburban life.

But the film goes off in so many directions, and Waters is so self-satisfied with shock and gross-out elements, that it wears out its welcome before we even get to the courtroom.

Beverly bakes cookies, keeps her home sparkling clean, knows the garbage collectors by their first names and every morning fixes the perfect breakfast to send off her dentist-husband Eugene (Sam Waterston, whose performance consists primarily of broad mugging) and their two teenage kids, Chip (Matthew Lillard) and Misty (Ricki Lake, a Waters regular who also hosts a daytime TV talk show).

But after the family has gone for the day, Beverly slips into the bedroom, where she keeps her autographed photo of Richard Speck, her personal audio tape from Ted Bundy and books and scrapbooks about other notorious serial killers. This is also where she goes to place obscene phone calls to that nasty neighbor down the street who stole a parking space from her at the local supermarket.

And as others in the neighborhood offend, they too will pay a stiff price.

This sounds like it has the potential to be great fun, in a very dark satirical way, of course. And there's no denying that there are some laughs.

But Waters is far from subtle, and after awhile some of the more disgusting elements are anticipated more with dread than glee. (Beverly impales someone with a fireplace poker, literally ripping out his heart; she sneezes in church, spitting on a child; a disgusting scene from the gory horror movie "Blood Feast" is shown; etc.)

There are also places where Waters' material is so threadbare that the humor depends entirely on the viewers' knowledge of such camp celebrities as Mink Stole, Traci Lords, Patricia Hearst, Joan Rivers and Suzanne Somers.

This is intentionally sick humor, of course, but even for those with a strong stomach or a very broad-minded sense of humor, there are places here where Waters simply goes too far.

Still, there is something delightfully perverse about Kathleen Turner trying to run someone down with her car as she cheerfully sings Barry Manilow's "Daybreak."

"Serial Mom" is deservedly rated R for violence, gore, sex, nudity, profanity, vulgarity and marijuana smoking.