collapse collapse

* Links

* Forum Menu

* User Info

 
 
Welcome, Guest. Please login or register.

* Who's Online

  • Dot Guests: 421
  • Dot Hidden: 0
  • Dot Users: 0

There aren't any users online.

* Board Stats

  • stats Total Members: 2449
  • stats Total Posts: 89739
  • stats Total Topics: 15325
  • stats Total Categories: 5
  • stats Total Boards: 63
  • stats Most Online: 1104

* Search



Author Topic: Help on manufacturing marks conclusion: "machine" vs "source" ?  (Read 23563 times)

0 Members and 2 Guests are viewing this topic.

Offline Joel

  • AFTE Friend
  • Posts: 1
Hi Everyone,

Greetings from Singapore!

I'm looking for some advice on terms used in conclusions for manufacturing marks on plastics (in particular plastic bags produced by blown extrusion).

Assuming some plastic bags were found to have similar striation marks produced during extrusion at the die, would it be more appropriate to conclude:

1. "The bags were manufactured from the same "machine", or

2. "The bags were manufactured from the same "source"


Listed below are the delimmas I'm currently facing with the above conclusions:

1. The use of the word "machine" implies that the configuration of the machine (Hopper, Extruder, Die, rollers) at the time of production contributes to the striations, which i'm unable to derive based solely on the striae observed.

However, looking at the bigger picture, if we include the shape, size, weight and other physical characteristics along with the striations on the bags, would it be appropriate to use "machine" in that case?


2. The use of the word "source" is more general and implies that only the die is involved in producing the striation marks.

If the die is transferred to a machine producing bags with the same physical attributes, i'm assuming the stiations and physical characteristics of subsequent bags produced would be similar.

In this case the use of the word "machine" would be erroneous.

Therefore, would the use of the term "source" in the conclusion be a more appropriate choice to include for this possibility?


I have included a journal link below on the manufacturing process of plastic bags for your reference.

Roux, C., Bull, S. & Olinder, S. PATTERN EVIDENCE | “Plastic” Bag Striations. Encyclopedia of Forensic Sciences 1181-1189 (2000)
http://linkinghub.elsevier.com/retrieve/pii/B012227215300593X


Thank you very much for your time and assistance.

Best Regards,
Joel


« Last Edit: April 11, 2012, 09:24:48 PM by Joel »

Offline Andy Carriveau

  • AFTE Member
  • ***
  • Posts: 106
  • Gender: Male
Re: Help on manufacturing marks conclusion: "machine" vs "source" ?
« Reply #1 on: April 12, 2012, 09:14:48 AM »
Hello,

When examining evidence and I am unable to determine the exact origin of the tool mark, I report that "Tool marks observed on the ?????? are identified as having been produced by a common source".  I think that using "machine" says that that machine will always produce the marks that you are observing, when it is a part/tool within the machine or process that produces the marks.  So, my choice would be to use "source".

ac

Offline Aaron Brudenell

  • AFTE Member
  • ***
  • Posts: 1176
  • Gender: Male
  • Groovy, yeah!
Re: Help on manufacturing marks conclusion: "machine" vs "source" ?
« Reply #2 on: April 12, 2012, 12:42:27 PM »
I like/agree with Andy's approach but you could also simply use the term "Tool" in a generic way as the harder of two objects or the source of said marks--that's the official AFTE definition but those outside of AFTE may not immediately presume that meaning.  Just be sure to define it that way at the point when it comes to interview or testimony.
Aaron Brudenell
Firearm Examiner
Arizona Dept. of Public Safety
520-746-4644

 

Countdown Clock

* Recent Posts

Re: Happy Valentine's Day! by Skip Richardson
[February 14, 2025, 02:55:00 PM]


Happy Valentine's Day! by Jessica Winn
[February 14, 2025, 12:58:55 PM]


Re: AFTE 2025! Book your hotel now! by Jessica Winn
[February 12, 2025, 05:45:34 PM]


Re: AFTE 2025! Book your hotel now! by Omar Felix
[February 12, 2025, 05:27:43 PM]


Re: AFTE 2025! Book your hotel now! by Skip Richardson
[February 12, 2025, 05:19:52 PM]


Re: Firearm Training Shorts by Jill Dupre
[February 12, 2025, 11:39:06 AM]


Supervisor/Tech Lead, FATM Unit, Maine State Police Crime Laboratory by Patrik Hertzman
[February 12, 2025, 11:18:58 AM]


Re: Firearm Training Shorts by Richard Amberger
[February 12, 2025, 11:17:41 AM]


Re: Firearm Training Shorts by Stacey Phetteplace
[February 12, 2025, 10:51:49 AM]


Re: Firearm Training Shorts by David Murphy
[February 12, 2025, 09:56:01 AM]


Re: Firearm Training Shorts by aagosto
[February 12, 2025, 09:54:04 AM]


Re: Firearm Training Shorts by Jennifer Floyd
[February 12, 2025, 08:15:36 AM]


Firearm Training Shorts by Ron Nichols
[February 11, 2025, 04:20:56 PM]


Assistant Lab Director Illinois State Police Rockford Laboratory by caryntucker
[February 10, 2025, 10:46:10 AM]


Lab Director Illinois State Police Forensic Science Center @ Chicago by caryntucker
[February 10, 2025, 10:40:14 AM]

* Headstamp Guide

SimplePortal 2.3.5 © 2008-2012, SimplePortal