Watching a press conference by law enforcement officials investigating
the Texas church shootings.

They just said that a number of expended rounds have been recovered that
will be sent somewhere that maintains a ballistics database to see if
the rifle used had been previously used in any other shootings or crimes.

So, contrary to some of the discussions we've had here in the past, it
seems there *is* a data base maintained of the unique markings on the
rounds fired from a particular firearm.

On 11/7/2017 1:01 PM, Keyser Soze wrote:
Mr. Luddite wrote:

Watching a press conference by law enforcement officials investigating
the Texas church shootings.

They just said that a number of expended rounds have been recovered that
will be sent somewhere that maintains a ballistics database to see if
the rifle used had been previously used in any other shootings or crimes.

So, contrary to some of the discussions we've had here in the past, it
seems there *is* a data base maintained of the unique markings on the
rounds fired from a particular firearm.



If it has been used in a crime...



Ah. That narrows it down somewhat I guess.

On Tue, 7 Nov 2017 12:38:18 -0500, "Mr. Luddite" wrote:


Watching a press conference by law enforcement officials investigating
the Texas church shootings.

They just said that a number of expended rounds have been recovered that
will be sent somewhere that maintains a ballistics database to see if
the rifle used had been previously used in any other shootings or crimes.

So, contrary to some of the discussions we've had here in the past, it
seems there *is* a data base maintained of the unique markings on the
rounds fired from a particular firearm.

I think you're referring to the Maryland requirement that a shell casing be provided the state for
every gun sold in the state. Here a while back the state found that of the thousands of shell
casings sent in, not one had ever been useful in the solving of a crime. I think they stopped the
requirement.

Here's mo http://www.baltimoresun.com/news/mar...107-story.html

I'm thinking a 'ballistics database' as used above might be a database of casings or bullets that
have been recovered from a crime scene.

Mr. Luddite wrote:

Watching a press conference by law enforcement officials investigating
the Texas church shootings.

They just said that a number of expended rounds have been recovered that
will be sent somewhere that maintains a ballistics database to see if
the rifle used had been previously used in any other shootings or crimes.

So, contrary to some of the discussions we've had here in the past, it
seems there *is* a data base maintained of the unique markings on the
rounds fired from a particular firearm.



If it has used in a crime...

--
Posted with my iPhone 8+.

On Tue, 7 Nov 2017 12:38:18 -0500, "Mr. Luddite"
wrote:


Watching a press conference by law enforcement officials investigating
the Texas church shootings.

They just said that a number of expended rounds have been recovered that
will be sent somewhere that maintains a ballistics database to see if
the rifle used had been previously used in any other shootings or crimes.

So, contrary to some of the discussions we've had here in the past, it
seems there *is* a data base maintained of the unique markings on the
rounds fired from a particular firearm.

My only question about this is how "unique" they actually are and how
consistent they stay over the life of the barrel.
If you understand anything about bore erosion, you have to question
the ID of a bullet from a new barrel compared to one 1000 rounds down
the road.
I am seeing a lot of discussion these days about the flaws in the
"science" of forensics.
I would also like to see someone comparing the bullets fired from 2
barrels made consecutively with the same rifling tools. Either the
"science" of striations is flawed or the "science" of tool forensics
is flawed.
I would agree that comparing bullets fired from a particular gun
fairly close together in the life of the barrel might be significant
but most of the "uniqueness" would be from the usage, not the
machining. It is valuable when they find a gun that was tested shortly
after the murder but comparing a bullet from the new gun to one from
1000 rounds later is more troubling.

wrote:
On 7 Nov 2017 18:01:49 GMT, Keyser Soze wrote:

Mr. Luddite wrote:

Watching a press conference by law enforcement officials investigating
the Texas church shootings.

They just said that a number of expended rounds have been recovered that
will be sent somewhere that maintains a ballistics database to see if
the rifle used had been previously used in any other shootings or crimes.

So, contrary to some of the discussions we've had here in the past, it
seems there *is* a data base maintained of the unique markings on the
rounds fired from a particular firearm.



If it has been used in a crime...

Wasn't Maryland collecting fired cases and a bullet from every gun
sold for a while?


Just the cases but the state stopped doing that.

--
Posted with my iPhone 8+.

wrote:
On Tue, 7 Nov 2017 12:38:18 -0500, "Mr. Luddite"
wrote:


Watching a press conference by law enforcement officials investigating
the Texas church shootings.

They just said that a number of expended rounds have been recovered that
will be sent somewhere that maintains a ballistics database to see if
the rifle used had been previously used in any other shootings or crimes.

So, contrary to some of the discussions we've had here in the past, it
seems there *is* a data base maintained of the unique markings on the
rounds fired from a particular firearm.

My only question about this is how "unique" they actually are and how
consistent they stay over the life of the barrel.
If you understand anything about bore erosion, you have to question
the ID of a bullet from a new barrel compared to one 1000 rounds down
the road.
I am seeing a lot of discussion these days about the flaws in the
"science" of forensics.
I would also like to see someone comparing the bullets fired from 2
barrels made consecutively with the same rifling tools. Either the
"science" of striations is flawed or the "science" of tool forensics
is flawed.
I would agree that comparing bullets fired from a particular gun
fairly close together in the life of the barrel might be significant
but most of the "uniqueness" would be from the usage, not the
machining. It is valuable when they find a gun that was tested shortly
after the murder but comparing a bullet from the new gun to one from
1000 rounds later is more troubling.


I think they are comparing casings, not bullets.

On Tue, 07 Nov 2017 13:13:40 -0500, John H
wrote:

I'm thinking a 'ballistics database' as used above might be a database of casings or bullets that
have been recovered from a crime scene.

.... and tested and cataloged and entered into the database in some
searchable form.
My bet, not that many.
I know on TV they are always saying "that bullet matches an open
murder from 10 years ago" but it sounds like TV bull**** to me because
that same show has some geek comparing the bullets under a microscope.
How cumbersome would it be to physically compare 11,000 bullets a
year, to maybe a few hundred thousand from past years, just from
murders? I understand computers could narrow the search but the minute
differences still require actually looking and using more than a bit
of opinion, the main flaw pointed out when they talk about the problem
with forensics.
The classic case is a guy in the US who was positively identified as a
murderer in Europe from fingerprints, confirmed by the FBI, Interpol
and local "experts" and it turned out he was never even in Europe.

On Tue, 7 Nov 2017 18:57:48 -0000 (UTC), Bill
wrote:

wrote:
On Tue, 7 Nov 2017 12:38:18 -0500, "Mr. Luddite"
wrote:


Watching a press conference by law enforcement officials investigating
the Texas church shootings.

They just said that a number of expended rounds have been recovered that
will be sent somewhere that maintains a ballistics database to see if
the rifle used had been previously used in any other shootings or crimes.

So, contrary to some of the discussions we've had here in the past, it
seems there *is* a data base maintained of the unique markings on the
rounds fired from a particular firearm.

My only question about this is how "unique" they actually are and how
consistent they stay over the life of the barrel.
If you understand anything about bore erosion, you have to question
the ID of a bullet from a new barrel compared to one 1000 rounds down
the road.
I am seeing a lot of discussion these days about the flaws in the
"science" of forensics.
I would also like to see someone comparing the bullets fired from 2
barrels made consecutively with the same rifling tools. Either the
"science" of striations is flawed or the "science" of tool forensics
is flawed.
I would agree that comparing bullets fired from a particular gun
fairly close together in the life of the barrel might be significant
but most of the "uniqueness" would be from the usage, not the
machining. It is valuable when they find a gun that was tested shortly
after the murder but comparing a bullet from the new gun to one from
1000 rounds later is more troubling.


I think they are comparing casings, not bullets.

Same deal.
If I have been firing cheap surplus steel case ammo that may be far
from clean, I doubt those marks would stay "unique" for 100 rounds.
I suppose a revolver or bolt action might do better but the act of
extracting a case that starts moving while there is still pressure in
the barrel is going to leave a mark if there is the slightest amount
of grit on the round. Extractors and firing pins wear, bolt faces get
banged up and things just change. As I said, if you get these things
in fairly quick succession they may be unique but not for many rounds
down the road.
Perhaps that is why Maryland abandoned the practice of saving pristine
new cases. It is more of an indication of the machines in the factory
than the gun a couple of years later. I bet they also figured out
cases from consecutive guns off the line were too close to call once
they started looking at them. People who make their living in
forensics certainly would not want to tell us it is all bull****.

On 11/7/2017 1:57 PM, Bill wrote:
wrote:
On Tue, 7 Nov 2017 12:38:18 -0500, "Mr. Luddite"
wrote:


Watching a press conference by law enforcement officials investigating
the Texas church shootings.

They just said that a number of expended rounds have been recovered that
will be sent somewhere that maintains a ballistics database to see if
the rifle used had been previously used in any other shootings or crimes.

So, contrary to some of the discussions we've had here in the past, it
seems there *is* a data base maintained of the unique markings on the
rounds fired from a particular firearm.

My only question about this is how "unique" they actually are and how
consistent they stay over the life of the barrel.
If you understand anything about bore erosion, you have to question
the ID of a bullet from a new barrel compared to one 1000 rounds down
the road.
I am seeing a lot of discussion these days about the flaws in the
"science" of forensics.
I would also like to see someone comparing the bullets fired from 2
barrels made consecutively with the same rifling tools. Either the
"science" of striations is flawed or the "science" of tool forensics
is flawed.
I would agree that comparing bullets fired from a particular gun
fairly close together in the life of the barrel might be significant
but most of the "uniqueness" would be from the usage, not the
machining. It is valuable when they find a gun that was tested shortly
after the murder but comparing a bullet from the new gun to one from
1000 rounds later is more troubling.


I think they are comparing casings, not bullets.



They are. The first report was "spent rounds" but was corrected later
to casings. Harry's comment makes sense. They are comparing the
casing to others found at crime scenes, not from the manufacturer.