Maryland Supreme Court makes it illegal to say which gun shot a bullet in ballistic testimonies

Originally published at: Maryland Supreme Court makes it illegal to say which gun shot a bullet in ballistic testimonies | Boing Boing


Wait til they hear about the validity of eye witness testimony.


‘Top Men’ are working on the problem…

The theory behind firearm identification is that microscopic striations and impressions left on bullets and cartridge cases are unique, reproducible, and therefore, like “ballistic fingerprints” that can be used to identify a gun. If investigators recover bullets or cartridge cases from a crime scene, forensic examiners can test-fire a suspect’s gun to see if it produces ballistic fingerprints that match the evidence.

But bullets and cartridge cases that are fired from different guns might have similar markings, especially if the guns were consecutively manufactured. This raises the possibility of a false positive match, which can have serious consequences for the accused.


One of the things I hated about shows like CSI and its various spinoffs was how it created such unrealistic expectations in the minds of the public about both the capabilities and degree of certainty in forensic science. “We have evidence that supports this theory of the crime” gets twisted into “we KNOW the crime happened this way because our EXPERT WITNESS here used SCIENCE and nobody whose job involves SCIENCE ever makes a mistake!”


This is a really great article.

Arson investigation should be added to the list along with the examples of bite mark analysis and fingerprints (most people are shocked to learn how much subjective interpretation goes on in fingerprint ID). Most of “expert” arson testimony in criminal cases is built on unproven folklore passed down from one arson investigator to another, with no basis in science. This WVU journal from 2016 is superb.

One hurdle that courts face in getting rid of these junk sciences is, unfortunately, the American bloodlust for punishment and the political pressure to make sure the people we’ve decided are bad guys don’t go unpunished. Even if it means a few eggs might get broken in the process.


Then, by all means, make it illegal for the gun lobby to block extensive firearm research, which they’ve been doing for fifty years or more.


In an ideal world, it sounds like, rather than making it inadmissible, it should be treated like other circumstantial evidences. Not proof by itself, but something to consider along with the totality of other evidence.

Of course, we don’t live in a an ideal world, and it may be that juries are too primed to think of this as proof to be able to objectively weigh it in context.


Everyone knows that looking for tooling marks is unscientific hokum. Ballistic dowsing is the cutting edge of criminology!


That’s more or less what the opinion is doing. Ballistic experts can still testify that the bullets are consistent or not consistent with the markings that come from a particular gun, just not that it came from that particular gun.


The part of The Dark Knight where Batman somehow does reconstruction of a shattered bullet in order to retrieve a fingerprint was really weird and stupid even if it was for a fantasy movie. He’s supposed to be a detective, not a wizard. And it didn’t even advance the plot in any way that I could comprehend.

Come to think of it The Dark Knight trilogy had several such scenes that may have sounded good in Nolan’s head but just failed to work on screen and should have been cut from the final edit.


It would have made more sense if they’d clarified that he had used an Interdigital Batsorter Anti-Crime Computer to make the forensic match.


with this, fingerprint, handwriting analysis, and on … the only way it should be allowed in the court room is if there’s double blind tests being run

if the analysts didn’t know whether the bullet or the gun was the one question for the crime - it’d be a different world. i suspect some times they might be able to tell, but there’s just so much confirmation bias going on


EXACTLY. Nolan’s Batman didn’t even label his equipment at all. How are we supposed to know what he’s even doing?


Every encounter leaves traces that crime scene investigators can find, but only during a murder. It’s not like the same place would also have any fibers or pollen grains lying around from the day before or anything.


batman is very smart, but also forgetful. labels help. pretty sure that’s why robin’s got that r on his chest


A common misunderstanding, but the “R” is actually for “Reggae Man”.


Even the villains used to label their henchmen for clarity.


Though you can tell that Penguin started phoning it in with the codenames after a while. Maybe he was just trying not to get attached.


this is what happens when you get knocked in the head enough times i guess. let this be a lesson to us all. ( although it does make “big label” very happy )


Several justices dissented, arguing that such firearm identification has been the “backbone of countless prosecutions,” an historically reliable legal device for sending people to jail.

“It got us the results we wanted, so let’s keep doing it, even if it isn’t accurate” isn’t a good reason to do something.

There are a lot of forensic science that isn’t as air tight as the experts want to make them out to be. Bite marks are an example that turned out to be horribly flawed.

Ballistics comparisons can be used as a tool. Caliber, rifling twist rate, and number of grooves can narrow down the model used, or exclude a suspects pistol from a recovered bullet. There are variations in the tool marks to create the rifling, but it doesn’t appear their variations are truly unique enough to discern which gun fired which bullet consistently. Even if it was 80% accurate, or 90%, that’s still a lot of people who might be falsely convicted.


I was prepared to be mad about this, but I am quite pleased with the actual content as opposed to the very click-baity headline. Forensics are at best complicated and mostly helpful in narrowing down options in a crime scene investigation, and while bullet matching is better than bite-mark matching (haruspication is slightly more accurate, and there is a really dark story behind the creation and pushing of bite mark analysis), it’s not infallible so this ruling is actually a good thing.