"I 've been thinking this over and I 've come to the conclusion that ballistic `` fingerprinting `` is the stupidest thing I have ever heard . As a crime fighting tool and especially a prosecutorial tool , it 's worth would be questionable and actually extremely damaging . The characteristics recorded ; land and grooves ( rifling ) on the projectile , breech face marks , firing pin indent and extractor marks on the spent cartridge case , could all be corrupted with the expenditure of about 20 minutes of easy work with a small file and/or a new barrel . For some of the more popular handguns , we 're talking $ 20 for a new barrel . Imagine the enterprising criminal with an extra $ 200.00 in his pocket . He could buy replacement barrels for a few of the more popular handguns and have a lucrative swapping out service . He trades out the first barrel and places the one now `` in hand `` in the next gun . No barrels need to be destroyed , all that needs to be done to defeat the system is have discrepancies between original manufacturer 's supplied projectile on record for a certain serial number gun and the crime scene recovered projectile . '' Lieutenant , this bullet the coroner recovered from Virgil 's head goes with serial number xw34t67 . The gun we found under Harry 's mattress , which we can prove killed Virgil , is number jy57p19 . What good does that do us ? `` Realistically , at that point would any further detective manhours be expended trying to figure out how this happened ? The barrels were swapped , any evidence as far as ballistic `` fingerprinting `` is concerned , is corrupted . Move on . . . How about the questions raised for the prosecution if say Harry does go to trial for shooting Virgil with only two marks matching out of four ? Let 's see , was the ejector swapped out too ? Maybe it 's reloaded ammo , it 's got three ejector marks on it , which firing was incidental to the criminal act ? Another important question ; would such a partial , 2 out of 4 or otherwise inconclusive match , ( which probably would not be offered as evidence or even admissible in court ) , be accepted as probable cause for a search or an arrest warrant ? The next , even more important question is : If the bullets ( original , supplied by manufacturer and the recovered crime scene bullet ) do n't match , does n't that open a Pandora 's Box of claims of `` I 'm being framed ! '' ? ? ? The defendant could claim that it was the police , not him , that swapped barrels . Harry says , `` the cops got a sample bullet from my gun and the bullet that done killed Virgil do n't match ! They put a different barrel in my gun that matches the bullet they said was in Virgil 's noggin `` The state would be providing four pieces of potentially ironclad exculpatory evidence for the defendant ! ( again , land and grooves on the projectile and breech face marks , firing pin indent and extractor marks on the spent cartridge case ) The defense will of course enter into evidence a STATE SEALED document attesting that the following data represents the official -- exclude all others -- `` ballistic fingerprint `` for Harry 's gun , S/N-jy57p19 . The problem for the authorities is , while they can prove that Harry 's gun killed Virgil , ( using standard forensic ballistics ) that fact does not matter anymore because the crime scene bullet , the one in Virgil 's noggin , matches a different gun , not placed in evidence by the prosecution and nowhere to be found . . . This would create a new level to the prosecutor 's burden of proof , now he has to prove beyond a reasonable doubt that THIS defendant also swapped the barrel and corrupted other `` fingerprints `` for his weapon in addition to actually firing the weapon that killed the victim . I think that more times than not , this will be an impossible additional hurdle to jump and the outcome of that will be allot of criminals will go free . This `` new `` science of ballistic `` fingerprinting `` would in essence destroy the well established and deserved good reputation of forensic ballistics . I think this proposal will work directly against law enforcement and in the end , help criminals . Debate questions : Does this ballistic fingerprint proposal , with all the inherent questions it raises , realistically help or hurt the police and prosecutors ? Does it increase or lessen the hours needed to solidify a case ? Can anyone prove to me that criminals will not go free using a corrupted ballistic `` fingerprint `` as their legal leverage ?"
"That crime fighting tool senario you just described is REALLY REALLY spooky . They way our justice system works is : 1 ) crime is commited 2 ) suspects are considered 3 ) evidence against one suspect builds and is arrested 4 ) suspect is given a fair trial with all the evidence present to a judge and jurry . In our system of justice , collection of evidence is PROHIBITED by the 4th Amendment without probable cause . There is no crime , thus no exuse to collect evidence . Citizens are also protected by giving any evidence against thier will by the 5th Amendment . This collected evidence will be used against suspects without thier permission . The crime fighting tool you just described violates 2 rights in one sweep . That is a very scary power given to police ."
"thinking this over defense will of course enter into evidence"
"REALLY REALLY spooky evidence against one suspect builds"