Experiment #21
Ultraviolet Examination
I. Objectives
Understand the techniques employed in the ultraviolet examination of physical evidence
in relation to entrapment cases.
II. Apparatus/Materials
Ultraviolet lamp, money bills, ultraviolet powder, camel hair brush, forceps, big white
mailing envelope, notebook and bond paper
III. Procedure
1. Get five money bills with different denominations.
2. Record each of the serial numbers in a notebook.
3. Get a piece of bond paper where the money bills are to be placed for dusting.
4. Dust each of the money bills with ultraviolet powder.
5. See to it that both sides of the money bills are covered with the UV powder.
6. Get a white business envelope and dust the inside portion with ultraviolet powder.
7. Place the dusted money bills inside the dusted envelope and seal it.
8. Hand-over the envelope to the subject who will be examined for ultraviolet powder.
9. Allow him to open the sealed envelope and to count the money bills which were taken
out from the envelope.
10. Wait until the money bills are placed inside his pocket.
11. Direct him to have his hands including the money bills and his clothing subjected to
ultraviolet examination inside the dark room.
12. Reproduce the money bills which are contaminated with UV fluorescent powder and
mark the areas which are covered with the powder.
13. Record and illustrate your observations.
IV. Observation
1. What is the color of the ultraviolet powder when used in dusting the money bills?
2. Why is it necessary to use the color of the powder which is similar to the color of
the money bill from which it is thinly applied?
3. Discuss any difference if UV fluorescent powder is viewed under the:
3.1. UV light
3.2. Visible light
3. What is the reason why UV powder must be thinly applied in each of the money
bills?
4. What is the purpose of sealing the envelope that contains the dusted money
bills?
5. What happens when the subject counts the dusted money bills from the envelope
which is handed-over to him?
6. During the conduct of UV examination on the subject and the money bills,
who/what is first exposed to UV light?
7. Where is the UV examination of the subject performed?
8. What is the source of the UV light?
9. What are the parts of the body of the subject that are exposed to UV light?
10. Give the results of the UV examination on the subject.
11. What is the reference standard used as basis for a positive finding?
V. Post Laboratory Discussion
Guide Questions
1. What is ultraviolet radiation?
2. Give the difference between far UV and near UV.
3. What are the wavelengths of the UV radiations used in ultraviolet examination?
4. Give the difference between:
4.1 .Ultraviolet light and visible light
4.2. Ultraviolet light and infrared light
5. What is ultraviolet examination?
6. Explain the principle of fluorescence.
7. Is ultraviolet examination effective in drug entrapment cases? Why? Why not?
8. Give other applications of UV examination in the field of criminal investigation.
VI. Conclusion
VII. Illustration
VIII. Documentation
