I can’t recall ever seeing a movie in which the lead character never changes her expression. But that’s how Hilary Swank plays Marissa, a newspaper editor whose son is murdered, in “The Good Mother.” When she’s told the news by her other son, a police officer, there’s no shock on her face, only the furrowed brow she wears through every minute of the film.

The dead guy’s pregnant girlfriend goes to Marissa with a clue about who the killer might be, and the two women team up to track down the truth. But Miles Joris-Peyrafitte, who directed and co-wrote the script, couldn’t decide whether he was making a movie about grief or a murder mystery. Sadly, he doesn’t do either very well.

He also makes odd editing choices. For instance, there’s a scene where the two women are playing pool — as you do when you’re desperately trying to find whoever shot your son/boyfriend. However, though we see them lean down with the pool cues, followed by the sound of the balls making contact and dropping into a pocket, we never see that action on camera. Perhaps it’s because the actresses weren’t skilled enough to make the shots, so he decided to add the audio in a foley session later. But it’s an odd choice because he could just as easily have made them converse in a different setting, like in a booth at the same bar.

The movie is also very dark, and not merely in tone. In most of the scenes, the characters’ faces are in shadow. Add to that some ominous music from start to finish and you have a film that’s not very appealing to watch. Although it only lasts 84 minutes and limps to an unsatisfactory resolution, it still drags, with sequences of cars on a highway or trains passing by that exist merely as filler because the central story is not very compelling.

I give “The Good Mother” a 2 out of 10. Opens tomorrow in theaters.