What mike is saying, toxicology results.
they test the blood for chemicals like drugs or poisons
and urine to for the same..
If this "flake blood" inside the silencer was Shelia's then it should come back positive for cannabis? if tested for drugs.
We know Shelia's blood test of toxicology came back positive for cannabis!! if the blood in the silencer came back negative then its not her blood and the case falls! we all know rabbits don't smoke cannabis.