When she whines about the pesky inconveniences of jury duty, Deena Mullen is strikingly unaffecting. But when she talks about the specifics of the O.J. Simpson case, and the monstrous brutality of the murders of Nicole Brown Simpson and Ronald Goldman, she is powerfully compelling, and so is the film made about her.

Mullen thinks Simpson is guilty as hell, and her account and insights should give even Simpson's few supporters second thoughts.

"Juror Number 5: 58 Days of Duty on the O.J. Simpson Civil Trial," premiering at 10 tonight on HBO (and airing five more times this month), was derived by producers Fenton Bailey and Randy Barbato from a one-woman show in which Mullen, a freelance theatrical-lighting director, described her experiences and reactions as a juror during the Simpson civil trial.

Unlike the farcical criminal trial, Simpson's civil trial was not televised. Also unlike the criminal trial, it ended with a virtual guilty verdict for Simpson.

Whoa now, let's back up: A "one-woman show"? With "Deena Mullen" on the marquee? It sounds like a transparent attempt to cash in on a brush with infamy.

But when she got the summons for jury duty in the summer of 1996, Mullen says, she didn't immediately associate it with the Simpson case and didn't know much about Simpson anyway. She thought he was an ex-basketball player.

"I just rarely think that anything of significance has anything to do with me," she says, perhaps disingenuously.

Her Little Miss Mullen pose is annoying and hard to swallow. Much of what she says in the prefatory stages of her presentation sounds like stuff she should be telling a therapist, not an audience. But once she gets into the content of the trial, she talks less about herself and more about the case. Her descriptions of autopsy photographs the jury was ordered to view are grisly and harrowing, with ghastly details not commonly included in TV news reports.

One gains a new appreciation of the sickening enormity of the killings from her reaction to those photographs. As various pieces of evidence are mentioned, one becomes stupefied and outraged all over again at the spectacular incompetence of the prosecutors in the criminal trial. At least a couple of them have gone on to transform stunning failure into gadfly media careers and seem happy with the notion of celebrityhood, however they got it.

For all the self-pitying elements in her monologue, Mullen doesn't seem to be vying for more time in the public eye or trying to hype her importance in the case. She seems to be searching honestly for some sense in all the madness, and to be exorcising demons that the trial dredged up. She calls herself a "keeper of the horror."

Bailey and Barbato illustrate Mullen's soliloquy with all kinds of audio and visual gingerbread, some of it relevant and some of it not. During testimony about Simpson's history of abuse, in the playback of a panicked phone call that Nicole Brown Simpson made to 911 when Simpson was assaulting her, we hear him scream, in graphic sexual terms, an accusation not heard in its entirety on newscasts. There is also footage of an unidentified young woman approaching Simpson on a beach and telling him she "always wanted to shake the hand of a murderer."

But along with such material, the producers throw in all kinds of glitzy graphics and bombastic sound effects, many of them cheap tricks.

Other things about the production are troubling. Although an audience appears to be present for some of Mullen's performance, we never hear a peep out of them--no response of any kind. And yet the closing credits include one for "audience warm-up." Somebody had to come out and "warm up" the audience? With what, O.J. jokes?

How much exactly did Mullen profit from this little Simpson show she put on? We are not told. She complains about the slavish, lavish attention of the press, but nobody forced her to appear on the "Today" show and on "Leeza" and, all duded up, talk about the case. The word "hypocrisy" does not seem irrelevant.

Bailey and Barbato also produce for HBO a series of occasional specials called "Shock Video," containing excerpts from erotic, or just smutty, foreign TV shows. The specials are undeniably entertaining and, beyond the shock value, say something about the quirks of other cultures, but the producers can't leave well enough alone; they accompany the excerpts with double-entendres spoken by a female narrator in a phone-sex voice.

They are, in short, not so much producers as overproducers, and at times in "Juror No. 5" they overwhelm their own material. Even so, with all those caveats and qualms, this is gripping TV--a reminder that the '90s have been a miserable mess of a decade even before we learned more than we ever wanted to know about the sex life of Bill Clinton.

Mullen and the filmmakers more than justify bringing up the Simpson case all over again. It not only won't go away, it should not be allowed to go away, whatever subsequent tragedies and horrors come along to push it out of the daily news.

CAPTION: Deena Mullen reveals details of O.J. Simpson's civil trial in "Juror Number 5" tonight on HBO.