u/InkyFellow

There is an opening scene I remember strongly where her and her mom are in the car, they see a dead animal on the side of the road and the teen girl protagonist explains that they keep a shovel and other burial tools in the trunk for this because burial makes the ghost go away.

I believe an abandoned asylum was part of the plot? I believe tied to the death of the ghost she teams up with? It was definitely a "solving a murder" book, but it may be a serial killer book as well.