Having a 3D laser scanner is all well and fine, but if a judge won't admit your scan data and the exhibits you create from it into evidence you might as well save the taxpayer's money.
By choosing the Leica ScanStation you are getting a very accurate 3D measurement instrument that has been demonstrated to have:
- General Acceptance
- Peer Review
- Known or Potential Error Rate
- Maintenance of Standards & Controls
If you recognize these factors as the five essential prongs of the Daubert Standard you are correct. Daubert provides a rule of evidence regarding the admissibility of expert witnesses' testimony during United States federal legal proceedings.
A public safety agency planning to deploy their new 3D laser scanner to crime or fire scenes with the intention of eventually taking that scan data into a federal court might at some point be subjected to a Daubert motion. A Daubert motion is a special case of motion in limine raised before or during trial to exclude the presentation of unqualified evidence to the jury.
When you to go to court with your Leica scan data for the first time, you will gain an even greater appreciation of the effort we have made over the years to prepare material for you to use in an evidentiary hearing. It starts with being able to direct you to over 100 (and growing!) case references where exhibits from a Leica ScanStation have been accepted in trials. We have peer-reviewed articles about the accuracy of our scanners, validation studies, testing by world renowned universities and more. Expert witness testimony by Leica Subject Matter Experts is also available and part of our complete solution. If you must meet the Frye Standard because your plans include bringing laser scan data into court in California, Florida, Illinois, Kansas, Maryland, Minnesota, New Jersey, New York, Pennsylvania, or Washington, our meticulous documentation will support you there as well.
Keeping in mind that there are non-Leica laser scanners out in the marketplace that choose not to publish their accuracy (and you need to look for the word "accuracy" when evaluating scanner performance specifications), it is comforting to know that when you finally go to court with your Leica ScanStation data you have the backing of company that truly understands the mission.
This statement is from the courtroom transcript just prior to Judge Cambell's ruling in 2011 that Leica ScanStation system product may be admitted into evidence and used as a basis for expert testimony without objection as to its scientific validity and reliability. In 2013, a U.S. Federal Court issued a Daubert ruling affirming the scientific validity of Leica ScanStation evidence. Read more here.
ScanStation C10 Calibration & QA
One of the five criteria for introducing scientific evidence into court under Daubert requires the establishment and maintenance of operational guidelines/protocols for conducting analytical testing, monitoring quality assurance and controls, periodic calibration checks and validations.
Our customers accomplish this through:
- Periodic manufacturer's maintenance and calibration
- In-house performance checks (validations)
- On-board performance checks
- Best practices and field procedures
We are regularly asked (mostly by prosecutors and detectives) to describe the accuracy of our ScanStation systems as well as our protocol for ensuring that out scanners are calibrated properly. This document was written specifically to address these kinds of questions. Leica - When it has to be right.
Surveying tripods – characteristics and influences
In the daily work of an investigator, he often doesn't think about the influence of accessories on accuracy. However, with precision surveys and measurements over long periods, the influence of accessories becomes significant. Potentially, one of the largest sources of measurement uncertainty can come from the stability of the tripod used at the scene. Working with the Department of Geodesy Engineering at Technical University of Vienna, Leica Geosystems has studied the effects of tripods on instrument accuracy.
The tripod requirements are defined by the International Standard (ISO 12858-2) in terms of height stability under load and torsional rigidity. In addition to these requirements, Leica Geosystems also evaluates the horizontal drift. For this paper, these three properties were tested on a range of tripods. Using the results, recommendations are made for which tripod to use depending on the instrument and the application.
The choice of tripod used with the Leica ScanStation is affirmed by this white paper
Leica Geosystems…when it has to be right.
Read Judge Clay's Daubert Ruling on ScanStation Admissibility
Case reference and portion of transcript: Leica - Daubert is Satisfied.pdf