Voucher Specimen
Definition
A preserved specimen formally deposited in a collection or retained in the case file as a permanent reference. In forensic entomology, the killed fraction serves as the voucher for the developmental stage present at collection.
- Core disciplines
- Entomology, botany, morphological analysis
- Permanent storage
- Natural history collections (under accession numbers) or case file archives
- Key function
- Enables future independent verification of species identity and forensic conclusions
Common questions
What is a voucher specimen in forensic science?+
A voucher specimen is a preserved sample or organism formally deposited in a reference collection or retained in case files as a permanent, verifiable record. It serves as the scientific anchor for identifying and verifying a species or evidence type in current and future investigations.
Why are voucher specimens important in forensic entomology?+
In insect-based investigations, the killed fraction of insects collected becomes the voucher specimen that documents the exact developmental stage present at the time of recovery. This permanent record allows independent verification of the evidence and supports conclusions about post-mortem interval.
How do voucher specimens work in botanical evidence cases?+
Plant specimens are deposited in a herbarium with a permanent accession number and collection metadata. This allows future independent verification of the taxonomic identification, ensuring the botanical evidence can be reliably traced back to the scene and re-examined if needed.
Related terms
- Chain of Custody
- The documented chronological record of who collected, handled, transferred, and examined a piece of evidence. For digital evidence, chain of custody includes...
- Acetolysis
- Erdtman's 1934 extraction method. The sample is treated with a 9:1 mixture of acetic anhydride and concentrated sulphuric acid, which dissolves cellulose...
- Barcode of Life Database (BOLD)
- An online reference library of DNA barcode sequences (primarily COI gene) linked to voucher specimens in natural history collections. Used to identify...
- Blank Control
- A sample known to contain none of the target material, processed in parallel with real exhibits to detect laboratory contamination. A positive...
- Database Gap
- The absence of morphological reference data or molecular barcode sequences for the taxa encountered in trade, particularly tropical invertebrates, many freshwater fish,...
- Ethanol Fixation
- Preservation of killed insect specimens in 70-80% ethanol. The alcohol denatures proteins and prevents decay, maintaining morphological structure for months to years.
- Hot-Water Killing
- The method of killing insect larvae by immersion in water at approximately 75-85 degrees C for 30-60 seconds before fixing in ethanol....
- Instar Determination
- Assigning a collected larva to first, second, or third instar based on body length, spiracle morphology, and mouthhook features. Instar determines which...
- Reference Sample
- A biological sample collected from a known individual (victim, suspect, or elimination source) for comparison against scene stains. Typically a buccal swab...
- Reference Slide Library
- A curated collection of prepared microscopy slides (hair scale casts, feather cross-sections, bone histology sections) from verified species, maintained for comparison against...
- Scene-to-Laboratory Transfer Record
- The portion of the chain of custody covering the movement of samples from the scene or mortuary to the receiving laboratory, including...
- Taphonomy
- The systematic modification of bone by environmental processes after death, operating over the burial or exposure interval. Includes weathering, soil staining, sun...
Explained in these topics
- Botanical Evidence Collection and PreservationA herbarium-deposited plant specimen that serves as a permanent, verifiable reference for a taxonomic identification made in a case. Allows future independent...
- Morphological Keys and Reference CollectionsA physical sample of known species identity deposited in a recognised natural history collection under a permanent accession number, with associated collection...
- Preservation, Labelling and Chain of CustodyA preserved specimen formally deposited in a collection or retained in the case file as a permanent reference. In forensic entomology, the killed fraction serv...