The thing I find the most baffling is that she stopped.
She (allegedly) goes on this killing spree during 2015-2016 and then stops for 2 years, before her arrest in 2018.
That seems very unusual, usually people who get a thrill from killing (for whatever reason) start with their first killing where they are incredibly careful. Then there’s usually a long gap where they decide they won’t ever do it again. Then they do. Then they realise that murders are quite easy to get away with and they ramp it up a gear. Then they start being careless and that’s when they are caught.
She seems to have committed all of these crimes in quite short succession and then just… stopped? Was an internal investigation started at this point? What happened to make her stop?