The slimmest interface with the fringes of the American pornopolis is what justifies the docudrama existence of Wonderland, a nervous-breakdown tribulation that retraces the 1981 Laurel Canyon murders involving, in one way or another, sex-industry über-schlong John Holmes. Mr. Wadd was little more than a junkie with a rep by the early ’80s, so what James Cox’s movie explores is an otherwise run-of-the-mill Los Angeles debacle of coke-zonked robbery and bloodshed. Does this smudge of celebrity residue make the incident crucial true-crime storytelling? Sincere and self-important, Cox and his co-writers clearly think so, dressing up their teary Holmesiad with digital front-page transitions, benchmark tunes, and that-was-the-summer-that-was nostalgia. The movie desperately seeks culture-moment iconicity, but barely acknowledges Holmes as an exploited freak in capitalism’s dankest subcellar. Instead, he’s merely a lovable, dreamy loser haphazardly hunting down the Big Score.

Val Kilmer, despite being six years older than his 1981 character, is far too robust and personality-plus to be convincing as Holmes, coming off instead as an ordinary post-noir anti-hero, lost and scrambling in Dopeville. That is, if you can get past Kilmer’s lingering Jim Morrison affect; Wonderland plays best as an imaginary scenario for the surviving Morrison’s addicted spinout among the bottom feeders in blow-era Hollywood. As if toggling between scag and trampled blow himself, Cox ricochets between tedium and music-video business, saturated and desaturated hues, Method mumbling and caricature, the Rashomon-style re-experience of sequences and sheer repetition. The movie is enthusiastically inhabited, particularly by Josh Lucas as the “Wonderland Avenue gang” ‘s snarlingly obnoxious frontman, Lisa Kudrow as Holmes’s estranged suburban wife, and M.C. Gainey as a grizzled fed. While Janeane Garofalo is relegated to the background and Christina Applegate is all but unseeable in the dealer-den shadows, Eric Bogosian makes a hilarious and fearsome Palestinian gangster, and Dylan McDermott reinvents himself as a biker-badass with a romantic streak.

No one’s to be trusted, of course, least of all Holmes, who may have played both ends against the middle in order to save himself. (The film comes to its own conclusions, remembering to splice in actual crime-scene photos during the climactic massacre; the real Holmes went into witness protection, dying of AIDS seven years later.) Jonesing for headlines and gossip-buzz, Wonderland is too look-Ma for its own good-the simple story of a doomed hop-hog over his head in bad shit could’ve hit the nerve if left to tell itself.