That is close, ny grandfather used a straight razor, not a fancy new fangled safety razor! "What kind of a fool would keep paying for blades for a razor?"
credentials - well, being an expert witness in untold cases is the best credential...
It can be hard to find what all statements were made by a prosecutor in every trial, including closing comments to help cast guilt.
What you CAN find is that SOP for processing a gun into evidence is to...