In this case, what evidence would they be contaminating to touch his jacket without gloves? They know it is either GZ's blood or TM's blood. Videos and pictures are taken at the scene, his clothes were collected at the SPD.
Since none of us were at the scene, and likely have no idea what CSI collected from Zimmerman, we have no idea how evidence was collected. Different crime scene labs have different protocol they require when evidence is collected (all require gloves, of course). Storage of large items is sometimes a consideration for certain labs.
"Wet Bloodstains
LINK
If the bloodstained item is large or not easily transported, then absorb the stain onto a 1" X 1" square of the cotton muslin as described in part 2E under dried bloodstains. Package it in paper (or plastic to prevent contamination of other objects). Bring it to a secured location, take it out of the container and allow the cotton square and the container to thoroughly air dry. Repackage in the original paper container or, if necessary, a new paper container. If a new paper container is used, then the air dried original container should be packaged with the cotton square. If possible, the investigator should also collect samples from unstained areas of the item for negative controls.
Advantages: Requires little storage space; fairly easy technique to perform; stain is concentrated onto a relatively small surface area.
Disadvantages: Investigator must decide which stains and controls to collect; investigator must have direct interaction with bloodstain."
BEM: Please provide your source for this information, TIA
