Why is the question of whether the injuries came from a stone or steel weapon important? How could scientists distinguish between the different types of weapons?

It is important in determining whether injuries/death was an accident or purposeful, and if purposeful, who, how and why did someone do it. They determine the weapon through the ligature marks left, the shape, force and impact of the injury, the location of the injury, and by analysing any fragments and trace evidence left on the wound