This is a well referenced look at BPA. The perspective is clearly science-based and unfettered by practitioner assumptions and biases. Rather refreshing, to put it mildly, and it also uncovers how BPA experts don’t agree with each other on basic spatter evidence.

https://arstechnica.com/science/2019/08/physicists-now-have-even-better-models-for-blood-spatter-from-gunshot-wounds/