AMERICAN Indian murder mysteries are in vogue, with three new titles available on video: Thunderheart, Shadow Hunter and The Dark Wind. While all rely on Indian mythology to jack up the mystery element, the end results are different. There is little doubt Thunderheart (1992, 20.20 Vision, 115 minutes) wins hands down in terms of production value, if little else. Val Kilmer plays a half-Indian FBI agent sent to the reservation to investigate a murder. Kilmer is assisted and re-educated by native Graham Greene on the ways of Indian culture along the way to exposing a scandal. The problem is that Thunderheart tries to do too much, making it the longest and least focused. It devotes so much time to Kilmer's personal struggle that even the most dedicated murder mystery fans will find the plot hard to follow. Stunning cinematography, but after a while it serves to highlight the film's pretentious and exploitative nature. Shadow Hunter (1992, 20:20 Vision, 93 minutes) is no less exploitative. Strictly speaking, this film belongs to the stalk-and-slash rather than the murder mystery genre. Scott Glenn plays a burnt-out big city cop sent to the reservation to escort an Indian homicidal maniac back to ''civilisation''. On the way, Glenn hallucinates, rams his car into a big cactus and the killer escapes. The rest of the film devotes itself to the pursuit of the super criminal, with every cliched stereotype thrown in for good measure. This includes the almost mandatory miraculous Indian tracking skills, more hallucinations, ambushes, etc. It is ironic, but The Dark Wind (1992, ERA, 106 minutes), which enjoys the lowest production value here, is the only proper brain-tickling murder mystery of the three. Lou Diamond Phillips plays Jim Chee, a wimpy, clumsy Indian policeman dragged into separate yet intertwining crimes. The Dark Wind relies little on dubious and tenuous references to Indian traditions and mythologies to keep the suspense going. It is also devoid of the cliched testosterone-charged, macho-machinations and stunts which carried the other two films. The Dark Wind is a rare film, not because of its Indian theme, but because it is a decent representative of the murder mystery genre.