Chemical presumptive narcotics identification systems, such as the NIK® Polytesting System and the ODV NarcoPouch® lines are some of the most widely-used field drug testing systems used in law enforcement today. Law enforcement officers are expected to combine their investigative skills and experience, knowledge of the characteristics of suspected narcotics and familiarity with the expected color reactions from field tests to correctly identify suspected narcotics.
To gain the maximum benefit from using these test kits, officers should incorporate the following twelve points into their testing protocols to generate accurate and consistent results and successfully establish probable cause to support arrests.
1) Use more tests
Presumptive drug testing systems are designed to identify compounds based on probabilities and the use of multiple tests in succession. The more tests used in the identification of a substance, the greater the probability of positive indication.
2) Don’t overload the test
Always use the correct amount of drug sample when testing. Never overload the pouch. If necessary, adjust the amount of sample according to the strength of the color reaction observed.
3) Break the ampoules in the right spot
Always break the ampoules in the middle of the special ampoule holder by pinching the holder between the thumb and index finger. Never use another instrument to break the ampoules. Most presumptive drug tests include glass ampoules. Break the ampoule in the wrong place and the glass can puncture the test kit (and your finger).
4) Not shaken or stirred
Completely agitate the pouch with the index finger while holding the pouch by the plastic clip in the opposite hand. Never shake the pouch up and down.
5) Use a white background
Always use a white background behind the test pouch to accurately identify the color results. If you view the test on a colored background, it will skew your perception of the test results and could result in a false identification.
6) Your results may vary
Color results are based on the quality and quantity of the drug in the sample. Cutting agents may shift the color hue from the color example printed on the pouch. These shifts should be expected and should be considered when interpreting results.
7) Always consider age
When testing for the presence of marijuana, the age of the plant should be considered when interpreting the results. Older plant material will take longer to react than fresher material.
8) Consider form when testing for Cocaine
Depending on the form of the Cocaine, the first ampoule of a Modified Scott Reagent test (Test G of the NIK Polytesting System) will vary in its reaction.
9) Take the high road AND the low road
Some compounds have multiple tests for presumptive identification. By using more than one test, the chances of a presumptive identification are greatly increased.
10) Three is better than two
Three ampoule tests are more discriminating than tests with one or two ampoules. This is particularly true with the Duquenois Levine and Modified Scott tests.
11) Never introduce liquids
When testing for liquids, place a small amount on a clean white tissue or paper. Never introduce liquids directly into the pouch for testing, except when testing for GHB.
12) Neutralize your tests
Always use an acid neutralizer before disposing of NIK tests, and ALWAYS wait for the test pouch to be completely neutralized before placing the safety clip back on the pouch. Do not handle the pouch after adding neutralizer, as it may generate substantial heat.