How to Properly Swab for Biological Evidence

To avoid contaminating evidence with your DNA.

To avoid transferring your fingerprints to the evidence.

To make sure you don't tear the gloves.

So when you are done collecting a sample you can throw away the top pair of gloves.

So you can take notes, etc. with a pair of gloves that haven't touched evidence.

So that if you touched the fingers of the first pair your DNA is covered by the second pair.

Plastic bag

Paper bag

Tissue paper

Swab box

Semen, saliva, blood, or other bodily fluids

Fingerprints, footprints, and tool marks

Hair, fibers, and paint chips

Documents, weapons, and drugs

The fingertips

The base end

Any part, as long as you're careful

The middle of the palm

To provide extra warmth to the hands.

To allow the outer pair to be used for notes or phone calls without contaminating the inner pair.

To make it easier to remove gloves quickly.

To prevent the gloves from tearing easily.

Immediately package the sample.

Fill out the information on a swab box.

Apply sterile water to the stain.

Take a photograph of the stain.

Case number, date, your name, and item number.

Type of biological evidence, location, and weather conditions.

Victim's name, suspect's name, and witness statements.

Laboratory analysis results and chain of custody.

Any cotton swabs available.

Pre-packaged sterile swabs.

Swabs with plastic handles.

Swabs that have been sterilized in the field.

Each swab should be packaged individually.

They can be packaged together.

They should be placed in a plastic bag.

They should be air-dried for 24 hours before packaging.