An escaped psychopath, institutionalized for the brutal murder of men who sexually abused her, stalks a teenage boy and his friends while a local detective chases her through town, determined to save her son’s life.

Who’s the protagonist?? The psychopath or the local detective.? If it’s the detective, then she should lead off the logline., not be tacked onto the end.? Particularly as she is the character with the positive goal.

So something like:

A detective must find and stop an escaped female serial killer before she kills her son.

But left begging is: why has the serial killer zeroed in on her son??? What has he done to “deserve” her attention?? A logline can’t explain everything, but every action laid out in the logline must make sense to a reader.

Also, It might be better to describe her a sociopath or a serial killer. (Technically, a psychopath is too out of touch with reality to function well enough in the real world to maintain a sustained activity of any kind.)

fwiw