You’ll have to excuse The Violent Heart. It knows not what it is.

No, really. In its quest to be a romance, it also pulls in elements of tragedy. Of course, that’s nothing new in cinema or literature, as love and loss are often intertwined. But Heart also wants to be a murder mystery, and therein lies its greatest weakness: lack of focus, silly developments and nonsensical twists.

As a 9-year-old, Daniel witnessed his older sister’s murder. Fifteen years later, he’s a young man (played by Jovan Adepo) trying to make something of himself. He’s a lube technician changing oil all day long, but also an ex-con who spent time in jail for blinding a boy during a fight in high school. He’s a good kid caught in a bad situation, but few people are looking to give a felon a second chance.

But that’s exactly what Daniel’s hoping for. He wants to join the Marines, but his past requires jumping through a few hoops and a lot of luck, and he’s been working hard to get his application right. Enter Cassie (Grace van Patten), a high school senior whose dad (Lukas Haas) is her English teacher, and is kind of used to getting what she wants. She meets Daniel by chance when Pops asks her to get the oil changed, and a ride to school turns into texting, which turns into a trip together. As Cassie grows closer to Daniel, she slowly draws away from her father, whom she begins to suspect is being unfaithful to her mom (Kimberly Williams-Paisley).

Writer-director Kerem Sanga’s sense of romance is really strong. There’s plenty of inherent conflict in the relationship Daniel and Cassie forge. He’s a good seven years older than her, and there’s the racial component and his criminal record. Adepo and Van Patten (niece of Eight is Enough stalwart Dick and daughter of filmmaker Tim) work well together, and it’s not hard to see why they’re attracted to each other.

Cassie pursues, and Daniel, knowing a romance with a high school student is potentially problematic, resists as much as he can. But he’s ultimately helpless against her charms.

That focus on his personal discipline is compelling, but Sanga adds in a bizarre anger management issue for Daniel. One scene in a bar finds him suddenly and seemingly for no good reason punching out another patron … as he is apologizing for hitting on Cassie. The flashes of rage don’t fit in with the measured nature of his character to that point, and after.

But once that’s established, the romance is brushed aside to resolve the Marines storyline and then transitions to a whodunit revolving around the murder of Daniel’s sister. The ultimate culprit, and his motive, is more than a little ridiculous, leading to a silly, melodramatic climax.

The Violent Heart has a good film inside it, but in cramming two more narratives into the main one creates a sticky, untenable mess, combining the worst in deus ex machina-type left-field conspiracy-theory endings that don’t serve the main narrative and drag the film down into the morass of mediocrity.