Twists and turns of a 1985 murder

True-crime aficionados will probably get the most out of “Killing for Love,” a documentary from Marcus Vetter and Karin Steinberger reexamining the 1985 murders of wealthy Virginians Derek and Nancy Haysom and the separate prosecutions that put their daughter Elizabeth and her German boyfriend, Jens Soering, a diplomat’s son, in prison.

College students in obsessive love at the time of the killings, their official narrative at the time of their arrest was that erudite wild girl Elizabeth’s seething hatred for her parents, whom she alleged were abusive, spurred her nerdy, knightly beau to do the deed. But the case becomes more complicated when Elizabeth’s about-face in testifying against Soering, his changed story about what happened, and unexamined clues suggest a different version of events.

Interviewing investigators, journalists and lawyers who first worked on the case — some of whom now questioning whether justice was served — the German filmmakers are fairly open in presenting their movie as an argument for their countryman’s release and repatriation to Germany. And it’s a convincing one. (Soering is interviewed; Elizabeth refused.)

Though overlong and pitched a little too heavily toward cable-TV sensationalism when long stretches of the young lovers’ overwrought mash notes are heard in voice-over by Imogen Poots and Daniel Brühl, “Killing for Love” is still a gripping murder mystery about the fated coupling of a pair of calculating romantics too smart for their own good and the limits of the American justice system.

“Killing for Love.” In English and German with English subtitles. Not rated. Running time: 2 hours, 3 minutes. Playing: Laemmle Royal, West L.A.