I worked in a medical lab for years, and have a comment about the EDTA tube issue.
Now, I won't get into the issue of the tampering seals being cut or anything like that, my comment is solely about the small dot of blood on the stopper of the tube and everyone questioning it.
That tube is an EDTA lavender topped tube usually used for tests that require uncoagulated whole blood such as a complete blood count or the like.
EDTA is an anti-coagulant and is present in the tube to keep the blood from clotting so the blood can be tested appropriately.
Those tubes are called "vacutainer" tubes and literally suck the blood out of you during venipuncture. To get the blood into the tube, you either draw the blood directly from a vein into the tube or you pierce the stopper with a syringe already containing blood to fill the tube.
The EDTA to blood mixture is important for proper testing etc, so the amount of vacuum in the tube is specific to only draw the needed amount for proper ratio.
Now, it is possible to remove the stopper and fill the tube "manually", but that is very uncommon and not really an accepted medical process (although it is occasionally done).
The "dot" of blood on the stopper is NOT indicative of tampering, but is actually what is present if the tube/drawing procedure is performed according to accepted guidelines.
I just wanted to give everyone this bit of info so as to keep the truth present in this case.
Thanks!
Edit: Here is a Youtube video showing a blood draw using an EDTA tube. You can clearly see the tube's stopper being pierced with the aforementioned needle.
This pic shows the fill tolerances of a standard ETDA vacutainer tube).
https://www.reddit.com/r/MakingaMurderer/comments/3ylijr/i_have_a_comment_about_the_blood_tube/