Field Test and Chemical Examination of Drugs – What Do They Prove?

When powder, plant material, tablets or another substance is found, the police will often perform a field test. A positive reaction may justify further investigative steps, but it does not by itself establish the precise type, quantity and characteristics of the substance.

What is a field test?

A field test is a preliminary method used to obtain an initial indication about a seized substance. A small sample is placed in a testing medium that produces a colour reaction. The result points to a possible group of substances and assists the authorities in deciding what immediate steps to take.

Because it is performed outside a laboratory, its result must be considered together with the seizure record, the expert examination and the remaining evidence.

Is a positive field test sufficient for conviction?

A field test does not replace the physical and chemical examination appointed in the criminal proceedings. Under Article 144 of the Bulgarian Criminal Procedure Code, an expert examination is appointed where specialist scientific knowledge is required. The laboratory analysis determines the nature of the submitted material within the questions assigned by the investigating authority.

The evidence is assessed as a whole. Relevant matters include how the substance was found and seized, whether the object examined is identical to the object seized, the expert’s conclusions and the evidence connecting it to the accused.

What can the chemical examination establish?

• whether the material contains a controlled narcotic substance or analogue;
• the type of substance identified;
• the net quantity of the examined material;
• whether separate packages have the same or different contents;
• other characteristics reliably established by the laboratory method used.

The scope depends on the appointment order, the materials supplied and the questions put to the expert.

Why are packaging and chain of custody important?

The material must be properly described and seized before laboratory testing. The record should identify the place where it was found, the packaging, quantity, field-test result and method of sealing. It must be possible to trace whether the object delivered to the laboratory is the same object that was seized.

Discrepancies in package numbers, missing signatures, damaged seals or uncertainty about representative sampling do not automatically have one predetermined legal consequence. They must nevertheless be examined because they may affect the reliability and evidential value of the analysis.

What should be checked in the case file?

• where and during which procedure the substance was found;
• how it was described in the record;
• which package supplied the field-test sample;
• which test was used and what result was recorded;
• how the remaining material was sealed and stored;
• which objects were submitted to the expert;
• whether the report answers the assigned questions;
• whether the records, photographs, weight and expert report are consistent.

Does quantity matter?

Type, quantity and value are relevant, but none should be considered in isolation. A minor-case assessment considers all circumstances. Where intent to distribute is alleged, packaging, communications, objects found and the other evidence are also examined.

Conclusion

The field test is a preliminary indication, while the chemical examination applies specialist knowledge to the substance. A proper assessment covers the entire chain from discovery and description to sealing, storage and delivery to the laboratory.

This article provides general information and is not legal advice for a specific case.

For advice concerning criminal proceedings involving drugs, you may contact attorney Mihail Tomov, a member of the Varna Bar Association.