Small dry evidence (like hairs, fibers, soil, paint chips, glass fragments, gunshot residue, tiny blood flakes, etc.) is generally collected using clean tools (forceps, tape, swabs, or scraping), placed into small secure containers (often paper packets/bindles, envelopes, or vials), and carefully labeled and sealed to preserve integrity and prevent loss or contamination. This is done following strict chain‑of‑custody procedures so the evidence can be trusted in court.

What counts as “small dry evidence”?

These are tiny, often easily lost materials that can transfer between people, objects, and places, such as:

  • Hairs, fibers, fabric fragments, feathers
  • Paint flakes, glass shards, building materials
  • Soil, dust, powders, gunshot residue, metal filings
  • Small dried biological traces (dried blood flakes, tiny skin flakes, dried secretions).

Because they’re fragile and easy to contaminate or lose, their collection follows very controlled methods.

General principles for collection

Across crime labs and forensic protocols, a few core rules show up repeatedly:

  • Do not contaminate: Use clean gloves and tools; change gloves between items when possible.
  • Collect the whole item if feasible: If the object with the evidence (like a small tool, clothing, or weapon) can be transported, it is often packaged intact rather than trying to lift every tiny particle on scene.
  • Protect from loss: Fine particles are kept in containers that won’t leak (vials, tubes, or bindles inside envelopes) and are sealed so nothing escapes.
  • Keep items separate: Each item or sample gets its own container to avoid cross‑transfer and mix‑ups.
  • Label and seal: Date, time, case number, location, collector’s name, and description go on the packaging, with seals signed to maintain chain of custody.

Common collection methods for small dry evidence

1. Picking with forceps or tweezers

For small but visible items (single hairs, paint chips, glass pieces):

  • A clean pair of forceps is used to pick up the item carefully.
  • The item is placed into a small container such as:
    • A paper bindle (a folded paper packet)
    • A small coin envelope
    • A glass or plastic vial with a tight lid.
  • The packet or vial is then placed in a larger envelope or box, sealed, and labeled.

This method is favored when the evidence is distinct and can be individually handled without breaking apart.

2. Tape lifting

When there may be many tiny particles in an area (fibers on clothing, dust, hair on upholstery, trace residues):

  • A piece of clear adhesive tape is pressed gently onto the surface to pick up trace materials.
  • The tape is then stuck to a clear backing card or acetate sheet, or placed adhesive side down on a suitable surface designed for lab analysis.
  • The card/slide is packaged in a rigid container or envelope and labeled.

Tape lifting is useful for collecting a “snapshot” of all trace materials from a defined area for later microscopic examination.

3. Swabbing

For tiny dried biological traces (e.g., small dried blood or body fluid spots) or residues on a surface:

  • A sterile swab is lightly moistened with sterile water or saline for dry residues (unless protocol specifies dry swabbing first).
  • The swab is rubbed over the area to pick up as much material as possible, often using a “double swab” technique:
    • First swab slightly moistened to lift the bulk of the material
    • Second swab dry, run over the same area to collect remaining traces.
  • Swabs are then air‑dried thoroughly (no heat, no direct sun) and placed into individual paper envelopes for storage and transport.

Swabbing is especially important when the object is too large or fixed in place to move, or when the residue is thin, invisible, or spread out.

4. Scraping

When dried material is caked or flaking (for example, dried blood or soil on a surface):

  • A clean, sharp tool (such as a scalpel or spatula) is used to gently scrape the material from the surface into a folded paper bindle.
  • The bindle is then folded securely and placed in an envelope, which is sealed and labeled.

This is a standard approach for dried blood on non‑movable objects if tape lifting or swabbing is not ideal.

5. Collecting bulk small dry material (e.g., soil)

For small dry materials that can be scooped (like soil, sand, powders):

  • Clean small tools (spoons, spatulas) or even gloved hands are used to collect a portion.
  • The sample is placed into a leak‑proof glass or plastic container with a lid, or into a paper bindle inside an envelope if leak‑proof containers are not available.
  • The sample is dried if damp to prevent mold and decomposition of organic components.
  • Control or comparison samples from nearby or relevant locations are also collected, labeled with depth or position if needed.

Packaging choices for small dry evidence

Different packaging is used depending on the type and condition of the sample:

  • Paper bags/envelopes: Preferred for dried biological stains or items with potential moisture, because paper allows air flow and reduces mold risk.
  • Paper bindles: Used inside envelopes for small loose particles (powders, paint chips, hairs) to prevent loss.
  • Leak‑proof vials or containers: Used for fine dry soils and similar trace samples to prevent leakage; also for liquids, if present.
  • Entire item packaging: If the object itself is small (e.g., weapon, garment, tool), it may be packaged whole in paper or other appropriate containers and sent to the lab without removing the trace at the scene.

Plastic is generally avoided for damp biological evidence unless it is being frozen, because trapped moisture can cause degradation and mold.

Documentation and chain of custody

For small dry evidence, documentation is as important as the collection itself:

  • The location, condition, and position of the evidence are documented (notes, sketches, and photographs).
  • Each item is labeled with case number, item number, description, date/time, and collector’s name.
  • Seals on packaging are signed across so any opening is obvious.
  • Every transfer (from scene to lab, between technicians, to storage) is recorded in a chain‑of‑custody log.

This ensures that the evidence can be traced and verified as the same material collected at the scene and that it has not been tampered with.

Mini story-style example

Imagine investigators at a burglary scene:

  • On a broken window frame, tiny glass fragments and a few dark fibers are visible. The investigator uses clean forceps to pick each fragment and fiber and places them into separate folded paper bindles, then into labeled coin envelopes.
  • On the suspect’s jacket, there’s no obvious debris, but the surface is likely to have tiny glass and paint traces. Clear tape is gently pressed onto the fabric in several areas, each tape strip mounted to a card and packaged individually with labels showing which part of the jacket it came from.
  • On the windowsill, there is a faint reddish smudge. A sterile swab moistened with distilled water is used to swab the area, followed by a dry swab; both swabs are air‑dried and packaged in separate paper envelopes, properly sealed and labeled.

Later in the lab, these small dry pieces of evidence can be examined under microscopes and with chemical and DNA tests to connect the suspect to the scene. TL;DR: Small dry evidence is collected using clean tools (forceps, tape, swabs, scraping), kept in secure paper packets, envelopes, or leak‑proof vials, and handled under strict labeling and chain‑of‑custody rules to prevent loss, contamination, or degradation.

Information gathered from public forums or data available on the internet and portrayed here.