Here is a question that has not been asked;
How would the prosecutor know my gun has a trigger job?
A gun in evidence may have been test fired, I do not know that the dissassembly and inspection of your gun would prove anything. That would be a case of evidence tampering.
Why do you think they take the gun in for evidence? To see if that is indeed the weapon used. Upon that inspection they're knowledgeable in firearms and their factory trigger weight I'm sure. They do it for a living. They can tell a light trigger from a not so light trigger.
Why test the trigger? In case it was an accidental discharge.
That's a weird question to ask man...lol
Sáncte Míchael Archángele, defénde nos in proélio, cóntra nequítiam et insídias diáboli ésto præsídium. Ímperet ílli Déus, súpplices deprecámur: tuque, prínceps milítiæ cæléstis, Sátanam aliósque spíritus malígnos, qui ad perditiónem animárum pervagántur in múndo, divína virtúte, in inférnum detrúde. Ámen