Here we go again! :) A blanket wouldn't have been put into a plastic evidence bag, especially if it had been wet with biological fluids. It would've been put into a brown paper bag which would have then been sealed closed. The rational is: 1. a blanket it too big for an evidence bag, and 2. the paper bag will allow the fluid to dry out, which is desirable for ease of examination for investigators. Otherwise it's all yucky and gross.