Agnès (Adèle Haenel) begins an affair with Maurice (Guillaume Canet), her mother’s assistant, in “In the Name of My Daughter.” (Cohen Media Group)

The French film “In the Name of My Daughter” is based on a tricky real-life story. It’s even trickier to write about without giving away spoilers, if that’s even the right word for details that are revealed about actual events. Let’s just say that the movie re-creates a scandal (and likely crime) that rocked the French Riviera in the late 1970s. The story is ripe for Lifetime movie treatment.

Director André Téchiné, to his credit, avoids the tacky tabloid feel of a mystery that’s been rehashed many times in the intervening decades, as this one has, in court case after court case. But while the movie begins as an authentically told human story, it ultimately becomes overwrought before the whole thing peters out during its final scenes.

“Daughter” opens with the introduction of Agnès Le Roux (Adèle Haenel), a 20-something heiress returning to France from Africa after a failed marriage, and Maurice Agnelet (Guillaume Canet), a lawyer and lackey for Agnès’s mother, Renée (Catherine Deneuve). Maurice greets Agnès at the airport because Renée is too busy running a casino on the French Riviera to perform shuttle duty.

This efficient opening lays out a few intriguing threads. From the first moment, the chemistry between Agnès and Maurice is clear; in another kind of movie this could certainly pass for a meet-cute. Then there’s the fact that Agnès is obviously displeased with her mother’s workaholic tendencies. When we see Agnès and Renée together, the story deepens. They have a sweet relationship, despite Agnès’s annoyance with her mother.

“You look beautiful,” Renée tells a groggy Agnès when the two reunite. “Liar,” Agnès replies with a smile, sending her mother into a little fit of laughter.

But if Agnès is hoping for some quality time with Mom, she isn’t going to get it, given that a Mafia type is in the midst of making a play for Renée’s business. The tension between mother and daughter builds after Agnès begins an affair with Maurice, who is angry with Renée for passing him over for a promotion.

The acting is spectacular, especially from Canet, who plays a convincing snake. He occasionally comes across as unassuming and even a little bumbling, but the truth is he’s constantly strategizing, in pleasure as well as business. (He may or may not be separated from his wife, and he has at least one other girlfriend in addition to Agnès.) Haenel, as Agnès, is an alluring figure, especially during the first part of the movie as she works through a divorce, a new love and major mommy issues. She ably conveys a perpetual sadness, even in moments of joy. But the emotional arc of the script does her no favors, ultimately reducing her to a desperate depressive with a tendency for stalking.

The movie’s pacing also feels off. The last fraction of the film jumps forward to a courtroom drama set many years later (complete with distracting makeup to age the characters). This section of the film is important enough to have inspired the English-language title. Yet these scenes feel tacked on like a postscript.

“In the Name of My Daughter” has good intentions of taking a sensationalistic riddle and turning it into a human story. But the pendulum ultimately swings too far, leaving an explosive tale behind in favor of one that fizzles out.

R. At Landmark’s Bethesda Row Cinema. Contains nudity, sex and strong language. In French with subtitles. 116 minutes.