"An inexperienced detective finds evidence at a murder scene strangely matching that found at her mother's death 20 years earlier and finds herself drawn into a vortex of deceit, terror and retribution"

"Murder" is too OPEN, can be more specific (like ?a character / age / locale / occupation of the victim i.e. ideally contrasting with her mother) "Murder of...."

Conflict & Stakes... MISSING!

"deceit, terror and retribution": Reaction... / The Action: MISSING!

more light can be thrown on the mother, apart from just being "dead", cos she is the only other character you've disclosed, its not really possible to empathise with either of them!

hope this helps...
Cheers!

The only part of this which means anything is everything before "and finds herself," but all that is too wordy. And while it might sound like it makes sense to describe the detective as inexperienced, if she hasn't been a detective very long, it's actually impossible, because she would never make detective without a great deal of experience to qualify her. That title may be new to her, but she ain't new to the job. So you could make it clear some other way, like so:

A young homicide detective becomes obsessed with her first case when it proves similar to her mother's murder twenty years earlier.

That's all we need to know to be interested in reading more about the story and this character. But whatever you choose to say about it, say it in the shortest way possible.

Descriptions such as "...finds herself drawn into a vortex of deceit, terror and retribution." are too vague, don't describe what the main action will be and what the goal is.

Therefore the plot is unclear.

Further if she "...finds herself drawn into..." the logline describes her as a passive protagonist. Why not make her compelled to achieve a specific goal instead?

This will make for a more compelling experience for the audience.

Hope this helps.