Too many officers would have immediately put themselves at risk by exposing themselves to give aid to the victim. Remember, you cannot be of assistance if you are injured or killed while trying to get to a victim. Personal feelings must not interfere with safety or common sense. As I will explain, in cases such as this, it is easy for your dog to miss a suspect who may be hiding within the building where there has been a large quantity of blood spilled. In such circumstances you cannot depend on your dog to effectively locate a suspect.
Blood is an extremely strong source of human odor.
Just as it is difficult for a dog to locate a large cache of drugs in a room, so it is with suspects in a blood soaked area. The scent is so strong it permeates the room and in some cases, the entire building with strong human odor. External odor given off by a suspect will not be as strong and therefore, difficult if not impossible for the dog to work with. You must be sure to clear every possible location for suspects as cautiously as you would without a dog. Conversely, a suspect who is bleeding, or covered in blood and has left the crime scene, will emit a strong odor and will be easier for the dog to track.