 conventional ninhydrin process |
 ninhydrin/zinc chloride/laser |
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conventional ninhydrin process |
ninhydrin/zinc chloride/laser |
The workshop is designed to be flexible, tailored to participant needs. Some familiarity with elementary science is assumed. One of its major goals is to acquaint latent fingerprint examiners with all aspects of laser detection of latent fingerprints. Alternative light sources are covered also. A range of physical and chemical procedures useful in conjunction with photoluminescence fingerprint detection on a variety of surfaces are dealt with. A second focus of the workshop concerns other evidence examinations by photoluminescence, including fiber analysis, document examination, explosives detection and nerve agent sensing. In addition, the workshop deals with spectroscopic measurement techniques which can impact evidence analysis. Finally, the scientific principles underlying photoluminescence detection generally are taken up to prepare forensic analysts for questions that might come up in court testimony and to provide the insight needed to keep up with anticipated future developments in the field.
The workshop includes both lectures and hands-on laboratory exposure for a total of 40 hours. Four Continuing Education Units will be awarded by Texas Tech University to those completing the program.
Argon-ion lasers, dye lasers and filtered lamps are available for the workshop. Photographic cameras and a darkroom are on hand as well. The laboratory is fully equipped with spectroscopic and imaging instrumentation. The instructional staff consists of Dr. E. R. Menzel, director of the center, and assistants. Instructional material includes the book Fingerprint Detection with Lasers, second edition, revised and expanded.
The fee for the workshop is $1,000/participant (banquet included). Transportation, food and lodging cost are the responsibility of the participant. However, the Center for Forensic Studies usually makes hotel reservations on behalf of the participants at government rates and provides transportation to and from the Lubbock airport, and to and from the university as needed. Maps may be accessed here for the City of Lubbock and the Texas Tech campus. A registration form may be printed and faxed.
The available laboratory facilities limit the number of participants to about 12. Accordingly, those wishing to participate in the workshop should contact the Center for Forensic Studies at the earliest possible date by e-mail to E. R. Menzel. The workshop is held annually in early January. In times of high demand, a second workshop may be conducted in late May.
CEU-carrying on-site workshops can be conducted for agencies that find this avenue more cost-effective than sending personnel to Texas Tech University.
Lecture 1 Mon. 8-10 A.M.
Fingerprints
Historical perspective
Overview of laser detection of latent prints
a. Inherent fingerprint luminescence
b. Dusting with luminescent powders
c. Staining with fluorescent dye
d. Chemicals that produce luminescent products
Types of lasers for fingerprint work (argon-ion, Nd:YAG, copper vapor,
He-Cd, dye)
Alternative light sources
Case applications
Lecture 2 Mon. 10:30 - 12 A.M.
Fibers, documents, body fluids, etc.
Traces of explosives, nerve agents
Laser operation and maintenance
a. Electrical and cooling installation
b. Cleaning and alignment
c. Fiber optics, lenses and mirrors
Laser safety
Optical filters and photography
Laboratory 1 Mon. 1 - 5:30 P.M.
Laser operation
a. Laser goggles
b. Electrical power and water cooling
c. Turning lasers on and off
d. Laser performance monitoring
e. Near-UV laser operation
Demonstration of luminescence detection of latent prints
Lecture 3 Tues. 8 - 9:30 A.M.
Details of luminescence detection procedures
a. Inherent fingerprint luminescence
b. Preparation of dusting powders
c. Ninhydrin/zinc chloride
e. Superglue in concert with luminescence examination
f. Difficult surfaces
Lanthanide chelates
a. Fingerprint detection
b. Traces of explosives
c. Nerve agents
Nanocrystals and dendrimers
Lecture 4 Tues. 10 - 12 A.M.
The physical basis of photoluminescence detection
a. Molecular states
b. Light absorption and emission
c. Fluorescence and phosphorescence
Laboratory 2 Tues. 1 - 5:30 P.M.
Laser operation, continued:
a. Cleaning of mirrors and Brewster windows
b. Laser alignment
c. Wavelength selection
d. Fiber optics cleaning and alignment
e. UV laser mirrors
f. Lenses, mirrors, filters
g. Water filters, heat exchangers, deionizers
The alternate light source
Lecture 5 Wed. 8 - 9:30 A.M.
Principles of laser operation
Types of lasers
Lecture 6 Wed. 10 - 12 A.M.
Spectroscopic measurements
a. Absorption
b. Luminescence
c. Lifetimes (phase and time resolved)
d. Intensified CCD cameras
e. Time-gated and phase-resolved imaging
f. Time-resolved scanning system
g. UV imaging
Instruments
a. Monochromators
b. Photodetectors
c. Electronics
Laboratory 3 Wed. 1 - 5:30 P.M.
Demonstration of spectroscopic measurements
a. Absorption
b. Luminescence
c, Lifetimes
d. Dye lasers
e. Time-resolved imaging
Photoluminescence in fiber analysis, document examination, explosives detection, nerve agent sensing
Laboratory 4 Thurs. 8 - 12 A.M.
Hands-on
Laboratory 5 Thurs. 1 - 5 P.M.
Hands-on
Laboratory 6 Fri. 8 - 12:00 A.M.
Hands-on
Laboratory 7 Friday 1 - 3 P.M.
Hands-on
Concluding discussion Friday 3 - 5 P.M.
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