Cassitterite , an oxide of beta tin, was the easiest tin ore to spot and to smelt. I have a series of specimens from Bad Schandau(??) which is ner the Czech border .The ore was usually a purplish color nd "Stuck out in alluvial deposits.(It would get "plucked out" of the mother granitic feldpars and quartzes and big melon size goobers could be found . Germany and todays Czech Republic were areas that were well known as major tin locations. Copper was available, but some of the best came from UK as "native" (pure) copper crystals. The stuff could be smelted and amalgamated by chimpanzees . Trial and error gave em the best (hardest) Mix ratios and they were off to the races.
Neat metal, bronze, lotsa tracking and sourcing can be done by todays modern isotope metallurgy tricks. We can tell pretty much which side of the county the ores came from, and copper and minor deposits of Sn, found in UK contained a bit of silver and bismuth, (the UK Cu had some gold in the xl structure too) so EDAX Xrays, and MAss Spec, by isotope and allotrope potting) can give us a fairly good road map of where the ores came from.
I love this kind of archeo technology and forensics crap. Like natures fingerprints let us know who was busy making better tools and when.
ARe they going to do any forensic style work with the childrens remains? seems like a bronze age cold case