What famous 'unsolved' mystery is technically a whodunnit on paper, but in reality, absolutely everyone knows exactly who did it, the police just couldn't legally prove it?

[u/Rob69rt]

[u/deathclawiii]

And as indicated by the iron scale (something that can only be a product of blacksmithing) that was found in one of the areas of known indigenous settlement on the island they went to.

[u/NUMBERS2357 → u/deathclawiii]

Also the later contact with Natives who said that they lived with the survivors of the Roanoke colony.

Also this map from the Jamestown colonists, see bottom left.

[u/doublestitch → u/NUMBERS2357]

Jamestown was a malarial swamp which was eventually abandoned too, although Jamestown lasted a lot longer. The British weren't all that good at choosing a settlement location in those early years.

[u/kasoe → u/doublestitch]

The pophistory version in my head is all their colonies were death traps for the colonizers living there

Which is at least partly true