Would like to know how others are solving the problems we see here.

We see a high number of thefts of scrap metals containing brass, copper, etc. The thieves are targeting agricultural and industrial sites and taking large electric motors, heavy gauge industrial electrical cable, irrigation pump impellers, etc. Most of what they take is set aside in scrap piles or bins for pick-up by legitimate dealers. Some is still usable and has merely been set aside (outside) for later use.

For thefts occurring before Sept 01 (50% rule) how are you proving
(1) the value of the material stolen, and
(2) metal composition?

For thefts occurring after Sept 1, same questions?

We are hoping to find some simpler solutions than what we have been doing.

I am very interested in this topic too. Interested in if need to obtain an expert to determine metal composition on a state jail?

Have you considered calling the scrap yard operator that the thieves are taking the stuff to? They're determining weight / percentage / value in order to buy the stolen goods, and sure seem to qualify as an expert witness under 702. Yes, they may not have the raft of masters degrees and PHDs that we're used to when we think about an "expert witness" but that's not the only qualification, don't forget that we're talking about "a witness qualified as an expert by knowledge, skill, experience, training..."

Can you use the representation of the sellor to the scrap metal dealer?

To supplement that, I would use the Expert approach.

Just had a case involving the prior version of the statute where proving the material was at least 50% copper was an element of the offense. As I was prepping it for trial, found myself thinking "Why didnt I file this as Burglary of a Building?" Sometimes the shiny new laws arent all theyre cracked up to be.