True, but that was not the scenario described.
The scenario described was a B&E where the civilian stole the evidence and turned it over to the police.
The chain of custody of said "evidence" is broken and becomes hearsay evidence. There is no verifiable proof of where the "evidence" was actually recovered from.
That would be like me walking into a police station and saying I found this 10lbs of coke in YOUR house. I would have to prove it came from YOUR house. Since it was removed, the proof of its origins would be difficult to prove.
As to the topic at hand, I found this interesting chart.
Take it for what it's worth.
Image
Great chart... really spells it out.