6) 3D Forensics

Question 1

Type of analysis that is based on physical evidence. The result is substantive and used to prove something in a court of law.
Has greater weight in trial.

Answer 1

Reconstruction

Question 2

Although it could be that the evidence is based in part on physical evidence, the result is demonstrative and is used to supplement an expert’s opinion. This has less weight at trial.

Answer 2

Recreation

Question 3

An example of documentation with manual tools is?

Answer 3

Stringing

Question 4

A 3D microscope provides high __________________ & then being able to make comparisons is what people people do in ______________. An example would be firing pin impressions.

Answer 4

Magnification

Ballistics

Question 5

Structured Light Scanners are often used for documenting medium sized objects. How does the fringe pattern one work?

Answer 5

Takes a number of stripes and it will alternate these stripes on a projector and then it pass through an object. Depending on how the patterns deforms it can recover some 3D information (can work in colour and also very fast).

Question 6

Structured Light scanners are often used for documenting medium sized objects. How does the structured dot pattern work?

Answer 6

Intel D515 Sensor
Hooks up to phone
Could capture a room/few rooms/a floor of an apartment
Recovers 3D geometry (ex: projecting pattern from sensor onto chair) with series of dots

Question 7

A _____________ _______________ has a point cloud which is a collection of millions of points that were captured by the laser scanner.

Answer 7

Laser Scanner

Question 8

Surveying method that measures distance using light.

Answer 8

LIDAR

Question 9

Can emit a very narrow bandwidth of light.

The beam can be focused so that it can travel over long distances.

Answer 9

LASER

Question 10

1) Laser pulse is emitted, and timer starts
2) Laser pulse is emitted & laser reacts off surface
3) Distance is calculated

Answer 10

Time of Flight Method (Pulse Based) to Determine Distance

Question 11

1) Multiple continuous waves are emitted
2) Waves reflect off surface
3) Outgoing waves are compared to incoming waves and distance is calculated

Answer 11

Phase Shift Method to Determine Distance

Question 12

Can be used for bullet trajectories and for shooting scenes
Shooting reconstructions
Trajectory analysis — Top down view, Side view

Answer 12

The Laser Scanner

Question 13

You combine photographs with laser scan data and when you bring it together you can do an analysis.
Those two rectangles are the path-volume envelope — the area that contains the swing of the object

Answer 13

Cast-off stains

Question 14

You can take the laser scanner, images from a CCTV camera, and you can make calculations based on a person’s __________.

Answer 14

Height

Question 15

One of the by-products of the laser scanner is that it creates panoramic images & one of the outputs is a ____________ _________.

Answer 15

Virtual Tour

Question 16

Interactive 3D Models are useful when…

Answer 16

You can capture an object, and don’t want people to actually hold it in their hands.

Question 17

3D Printing is useful because…

Answer 17

You can take it into the courtroom and they can look at it.

Being able to hold something in your hands helps you to remember & learn something about it.