SWGIT

Question 1

What does SWGIT stand for?

Answer 1

Scientific Working Group on Imaging Technology

Question 2

What is the mission of SWGIT?

Answer 2

to facilitate the integration of imaging technologies and systems within the criminal justice system by providing definitions and recommendations for the capture, storage, processing, analysis, transmission, and output of images

Question 3

Describe the membership of SWGIT

Answer 3

Those selected for membership in the group are experienced professionals working in the field of imaging technology or a related field and demonstrate the willingness to participate by consulting on the release of best practices and guidelines for the use of imaging technology in the Criminal Justice System.

Question 4

What is the purpose of the SWGIT document?

Answer 4

To familiarize the reader with important considerations in the capture, preservation, processing, and handling of images, no matter the image type and where they can find related guidelines and details.

Question 5

What are the basic requirements for the admission of digital images?

Answer 5

The images must be relevant, properly authenticated digital images that accurately portray a scene or object are admissible in court

Question 6

What is image compression?

Answer 6

Compression is the process of reducing a digital file’s size.

Question 7

What are the two types of compression?

Answer 7

The two types are lossy and lossless

Question 8

What is Lossy compression?

Answer 8

When lossy compression is used, critical image information can be lost and unwanted artifacts introduced as a result. Can also result from multiple saves.

Question 9

What is lossless compression?

Answer 9

Does not affect the image information as much. Is the preferred type of photo when it is subjected to scientific analysis

Question 10

The requirement that an exhibit (image) be authenticated is usually satisfied when what?

Answer 10

An exhibit is authenticated when there is sufficient evidence that the exhibit is what the proponent claims it to be (i.e witnesses in the case can do this)

Question 11

In the case of images processed using advanced equipment techniques, ________ witnesses must be able to testify concerning the ____ ____.

Answer 11

In the case of images processed using advanced equipment techniques, qualified witnesses must be able to testify concerning the processed used.

Question 12

Define a “primary” image as opposed to an “original” image

Answer 12

A primary image refers to the first instance in which an image is recorded onto any media that is a separate identifiable object. An original image is an accurate and complete replica of the primary image, irrespective of media.

Question 13

According to SWGIT, original images should not be _________.

Answer 13

altered in any way

Question 14

Processing should be performed on _________ images only

Answer 14

working

Question 15

What are the 5 methods for maintaining integrity?

Answer 15

1. Written Documentation
2. Physical Security / Environment
3. Redundant Physical Copies
4. Logical Security (WAN / LAN)
5. Third-Party Escrowing

Question 16

What are the 2 simple and approved methods that to not require technology for demonstrating integrity?

Answer 16

Visual Verification & Written Documentation

Question 17

To achieve maximum detail, it is the best practice to _________ the _______________ with the impression.

Answer 17

Fill the frame

Question 18

The minimum pixels per inch (ppi) resolution to capture a latent print is _________________.

Answer 18

1000 pixels/inch at 1:1

Question 19

Given that the 7D camera has a pixel resolution of 5184 x 3456, what is the maximum field of view that will yield the minimum resolution for a latent print?

Question 20

It is recommended to capture using _____ ___________________ or ___________________ _________________.

Answer 20

compression or lossless compression (e.g. RAW or TIFF)

Question 21

In regards to the first photograph… When appropriate (e.g. crime scene), capture overall view of impression area _________________ ___ scale, using proper lighting

Answer 21

without a scale

Question 22

In regards to subsequent photos… Capture overall view of impression ____________ ____ scale, using proper lighting.

Answer 22

with a scale

Question 23

The camera must be placed at a _____ degree angle to the impression.

Answer 23

90˚

Question 24

The scale must be placed on the same _________________ and ____ __________ ___ _______________ to impression without ____________________ _________________.

Answer 24

on the same plane; as close as possible; obscuring detail.

Question 25

The scale may contain 6 bits of information to identify the print. What are those bits of information?

Answer 25

a) Case number or unique identifier
b) Date
c) Initials
d) Source
e) Process used
f) Location/orientation
At a minimum, the scale should have the date and the initials of the photographer.

Question 26

What is the minimum megapixel native resolution recommended?

Answer 26

eight (8)

Question 27

Two sets of overall, mid-range and close-up photographs should be taken. What is the difference between the two sets?

Answer 27

One has markers and scales and the other does not

Question 28

How should the camera be positioned relative to the impression?

Answer 28

parallel and 90˚

Question 29

Where should the lens be focused on the impression?

Answer 29

Bottom of the impression

Question 30

What f-stop setting is recommended for optimum depth of field and image sharpness?

Answer 30

generally two stops below the largest f-stop

Question 31

Scale should be on the same level as what?

Answer 31

as the impression.

Question 32

What formats of compression are required?

Answer 32

uncompressed or lossless
compression. (e.g. RAW or TIFF)

Question 33

In addition to an overall footwear impression photograph, what areas of the footwear should be photographed separately close-up?

Answer 33

the heel and toe box area should be taken

Question 34

What is the procedure for photographing long tire impressions and what type of scale should be used?

Answer 34

a series of overlapping photographs of 12 inches each
should be taken; a tape measure

Question 35

It is recommended that lighting be rotated around a footwear impression to capture detail on the bottom of the impression. What is the minimum number of images that should be taken with different lighting? What is the spacing of the light in degrees as it is rotated around the print?

Answer 35

3 images; 100 degrees