On the first episode of The Shield, Detective Vic Mackey (Michael Chiklis) shoots a fellow Los Angeles cop in the head; the bullet ends an undercover investigation into Mackey’s corrupted police squad. A few episodes later, another cop tells superiors that he saw Mackey pocket cocaine from a drug bust. But Mackey catches the rookie having sex with another man, and simple blackmail gets Internal Affairs off his back for another day.

The Shield moves so quickly that it took me a while to appreciate the irony: the rookie’s shame about being gay may have saved his life. Maybe it wasn’t a brilliant plot device, but at least The Shield delivers some solid storytelling. You can peel the layers off this onion without its caving in on itself, and I can’t say that about anything on free TV since the first season of Survivor. Proving that there’s some justice in this world, The Shield has become a hit for FX, the basic-cable sister of the free-TV Fox network. (It airs Tuesdays at 10 p.m., with new episodes running through June 4.) The fact that it didn’t end up on Fox — which is desperately trying to replace Ally McBeal and The X-Files — says something about the future of the major networks, and it ain’t good.

In building a show around a cold-blooded killer, FX was clearly inspired by HBO’s The Sopranos, and though The Shield isn’t quite as clever, it’s about as addictive. Like mob boss Tony Soprano, Vic Mackey is a bald, large-framed guy of about 40 who has a bad temper and a slippery sense of morality. In another parallel, Mackey has problems with both his " families. " His wife complains about his long absences, and his son is autistic; meanwhile, the cops on his task force don’t seem capable of driving around the block without his guidance.

The Shield is about midway between free TV and HBO in terms of nudity and violence, and several sponsors have pulled out of the show on the grounds of bad taste. ( " Rigor or no rigor, that’s serious rack, " says one cop upon seeing a well-endowed female corpse.) FX isn’t likely to tone down the show; if it’s no more offensive than NYPD Blue, there’s no point in airing it. True, The Shield does have roots in more-conventional cop shows: creator and producer Shawn Ryan was once a writer for Nash Bridges, and several episodes are directed by Clark Johnson, who co-starred on Homicide: Life on the Street. But it seems significant that the cop eliminated in the first episode is played by Reed Diamond, another Homicide regular.

How can The Sopranos and The Shield get away with depicting murderers as heroes? The obvious answer is that they’re law-and-order fantasies, in which father figures do whatever is necessary to keep peace on the streets. Like Tony Soprano, Vic Mackey is a bad guy who protects us from the really bad guys. (Tony is more obviously corrupted, since even his " legitimate " earnings come from extortion — but police unions can also be pretty persuasive when their contracts come up.) By this reasoning, The Shield is a successor to the Dirty Harry and Death Wish movies, and Mackey’s pummeling of suspects in the interrogation room does hark back to the days before Rodney King. There are also stock characters straight out of the reactionary crime-drama handbook, including the cerebral detective whose non-violent methods almost always fail (Jay Karnes, a comic-relief version of Homicide’s Kyle Secor) and the by-the-book police captain whose moral rectitude is a cover for his intense political ambition (Benito Martinez).

But I don’t think the show’s appeal is that simple. Crime has decreased in real life, and in contrast to the violent dramas of the 1970s, The Shield doesn’t give much screen time to the loathsome but generally inept criminals before they’re captured, so it can’t really be charged with exploiting feelings of anger. And even Clint Eastwood would be disgusted by the behavior of Mackey’s men: the most deranged cop urinates on a subject, and when one of the group shoots a man in a case of mistaken identity, Mackey plants a gun on the body.

Instead, the popularity of both Tony Soprano and Vic Mackey may have more to do with the universal appeal of self-preservation. Tony and Vic are doing anything they can to keep their lives together, and even if we can’t identify with their methods, we can understand their motives. A series about an anti-hero on the way up — Tony Soprano before he got his McMansion in New Jersey, or Vic Mackey before he bullied his way into an untouchable position on the LA police force — would probably not be as popular. (Fox’s 1996 drama Profit, about an amoral man climbing to the top of the business world, was cancelled after only a few episodes.)

Of course, the programming executives at the older networks may regard FX and MTV (home of this spring’s other big hit, The Osbournes) as villains making their way up in the world. But they really can’t complain. After all, ABC has cancelled The Job and Once and Again while keeping creaky old programs like The Drew Carey Show and NYPD Blue, and WB is actually inflicting a remake of Family Affair on us this fall. Now that’s cruel.