Cops can't catch the homicidal maniac in "Halloween II," but a TV news crew manages to be Johnny on the spot at the scene of most of his murders. Instead of "oh, the humanity," the TV newsman warns the townsfolk of ill-fated Haddonfield, Ill., that ghastly, blood-curdling traffic snarls have resulted from the killing spree. "The streets," he gasps, "are . . . just . . . jammed!!!"

Gridlock -- the ultimate nightmare.

Traffic patterns would have made a more diverting source of modern mayhem than the computer-generated, John Carpenter-Debra Hill screenplay for "Halloween II," a splashily bloody, tediously idiotic, doggedly inevitable sequel to the big moneymaking mood piece "Halloween." Surely even the teen-age and hairy-ape trade must be tiring by now of the tattered and repetitious kind of cheap frights that this film, opening today at area theaters, dishes listlessly out.

The sequel, directed not by that haute auteur Carpenter but by Rick Rosenthal, begins with the last scene of the first film and meanders off from there. It becomes apparent early on that the whole film will take place the same night as the first and, indeed, broad daylight doesn't dawn until the very last frames. At least if there is a "Halloween III" it will have to take place on another day. Maybe it will cover the period from breakfast to lunch; you can pile up a lot of corpses in the morning if you try.

At the end of the first film, the maniac was shot six times by Donald Pleasence, who so furiously overplays the Van Helsing figure of the case -- a top shrink at a mental hospital from which the killer escaped -- that he seems a more virulent threat than the maniac. In the sequel, Pleasence pumps about six more bullets into the critter, but he keeps popping back up and skulking about, walking so slowly that one would think any potential victim would have sufficient time to flee the coop.

Pleasence also gets to utter the film's shabby excuse for an author's message, or an author's justification as the case may be: "We're all afraid of the dark inside ourselves."

The creators of the first film have boasted of its lack of gore and how atmospheric it all was (ploddingly dull, too); the sequel throws the synthetic blood around more liberally, and in some cases with daffy irrelevance. The camera lingers, for instance, on the blood pouring from the mouth of a child whose mother has brought him to the hospital where the killer will eventually set up his headquarters; the mother and child have no function in the plot line and never come into contact with any of the principals.

Jamie Lee Curtis -- looking much older than springtime -- is again the chief menacee. The screenplay reveals that there is a reason for the killing spree after all: The character played by Curtis is really the poor fellow's other sister, the one he didn't kill 15 years ago; he's killing everyone else in town to get to her. Perhaps in the next chapter the filmmakers will tell us what this chap has against sisters. The prevailing mentality is so cynical that it assumes audiences will demand nothing in the way of cogent explanations or character motivation as long as the killing keeps up at a snappy clip.

And so a fat security guard gets a hammer in the head, a shapely nurse is scalded to death in a runaway Jacuzzi, another nurse gets a needle in the temple, and so on. As the doctor, Pleasence at one point takes aim at an innocent youth in the street, mistaking him for the killer; the boy isn't shot, but a car rams him into a truck and he's incinerated in the ensuing explosion. It is later determined that the youth was not the killer, but nobody expresses a care that he was pointlessly snuffed; it never even occurs to anyone to send a note of apology to the kid's mom.

As far as technique is concerned, the movie is relatively free of Carpenter's languorous tracking shots, and less of it has been shot from the killer's point of view. The only real suspense that is generated is in trying to guess from which side of the frame the killer will spring (for the first murder, the most effective, he bounces up from the bottom). Other than that, it's a startle movie, not a horror movie, and suffocatingly silly even on that level.