Forensic Pocket Guide

Processing

BLOODSTAINS

Search for and analyze stains that are present within the crime scene, searching for stains that are potentially blood.  Bloodstains fall into one of three categories:

Passive Bloodstains

Transfer Bloodstains

Projected Bloodstains

Document any stains of interest during your initial overall, mid-range and close-up crime scene photographs.

Attempt to differentiate the different stains from one another.  Assign photo markers to each different bloodstain pattern.  

Re-take overall, mid-range, and close-up photographs of crime scene with photo markers in place.

Take examination quality photographs of each individual bloodstain pattern.  Include a scale in each photograph.  Utilize a tripod with a level to ensure that the camera is at a 90 degree angle in relation to the bloodstain when possible.  Fill the photo frame with the bloodstain.  

When needed, presumptive blood tests can be used to aid a crime scene investigator in determining which stains within a scene should be collected.  Use the appropriate DNA collection technique to collect samples of the bloodstains located throughout the scene.  Include the following swabs:

A swab from each individual bloodstain pattern

A swab of the beginning, center and end of each blood trail

A swab each time a single bloodstain pattern changes surfaces

There may be bloodstains within the crime scene that it would be beneficial to enhance like patent prints or shoe impressions.  Use one of the following to enhance select bloodstains:

Acid Fuchsin

Acid Yellow 7

Acid Violet 17

Amido Black

Coomassie Blue

Crowle’s Double Stain 

DAB

Leucocrystal Violet

Merbromin

 

 

Re-take examination quality photographs of each of the individual bloodstain patterns that were enhanced.  Include a scale in each photograph.  Utilize a tripod with a level to ensure that the camera is at a 90 degree angle in relation to the bloodstain when possible.  Fill the photo frame with the bloodstain.