The scene of a homicide usually contains biological hazards due to bodily fluids from the victim or suspect.  The crime scene investigator is prepared to handle the scene because they have their PPE, personal protective equipment.  The CSI is cognizant of the bio-hazards and completes the task of crime scene processing while wearing the respective PPE. Most of the CSI's even realize the problem with the Bio-Waste produced at these scenes, such as, the used PPE and the proper disposal of the waste.  The CSI wears their PPE and properly disposes of the produced bio-waste, great!  They have accomplished all their responsibility at the scene in regards to the biological hazards, or have they?  What about their equipment?  Has it been decontaminated?  What about the "visitors" at the scene, are they safe from contamination?

The decontamination of ourselves, visitors and equipment has not been addressed at the crime scene.  One solution to this program is the setting up of a decontamination zone at the scene of the crime.  This is an area identified by the CSI where equipment taken into the scene can be placed without worry about contamination.  This is also the area where the CSI can decontaminate themselves or their PPE.  The same area should be used by the visitors entering the scene  and either use the appropriate PPE or decontaminate themselves afterwards.

The decontamination area is designated after the CSI has thoroughly examined and documented the scene by photographs, notes and sketches.  The simplest method to set up a decontamination zone is by using a plastic drop cloth on the floor and having a 5 gallon plastic bucket 1/5 filled with a 10% solution of bleach and water.  The bucket should contain a sponge or brush to wipe down the equipment or the PPE.  Adequate supplies of PPE are maintained in this area along with a designated bio-waste container.

Setting up a decontamination zone requires very little effort on the CSI's part and the equipment required for the decontamination zone is easily obtained.  This zone would solve several issues at the crime scene.  It will eliminate the problems associated with biological hazards present and reduce the amount of contamination to the equipment, CSI, visitors and evidence containers.

I would recommend the use of bio-hazardous signs at the decontamination zone to help in the reduction of personnel at the scene and also address the liability issue of having a well defined bio-hazardous crime scene.  The precautions taken at a bio-hazard scene will help to reduce any questioning by the defense in regards to possible cross contamination from visitors, yourself or your equipment used in other crime scenes.  A safe scene is the best scene.