Good point
I got that from watching too much Time Team, not Investigation Discovery.
Stratified layers are where it's at, and man, do they love finding something dateable like a coin or a piece of pottery in the bottom of a ditch or under a foundation.
EDIT: But yeah, stratification is important in crime scenes, too, just on Time Team, the murders tended to be done by Saxons eleven hundred years ago. Still a bunch of skeletons involved.
But yeah, anything dateable can be really useful for context, but it's important to remember that we all have items in our houses that are ten, twenty, even fifty years old. I've got several books, heirlooms, that were printed in the 1870s. Cast iron pots from the '70s. That's normal.
But if a body was found, and the grave was thought to be 'historical', but then when the corpse was removed, a Coke can from no more than ten years ago was found underneath, it's time to question.
A body wearing clothing all thought to be ten or more years old is also a question mark, but not a big one. People have old clothing, but also, charity shops and vintage fashion is a thing. It's all about what the totality of evidence is telling you.
MOO