Here is the photo that my post was questioning, it is not blood on the glass shower door:
http://juror13lw.files.wordpress.com/2014/04/10.jpg
There are 12 marks.
Definitely not blood. It looks like small pieces of tape to me. Could it be something used to lift fingerprints?
On Edit: O.K., after reading more comments, it may be blood spots that are too small to see from the photo.