Just some food for thought.
Thing's we can point out, which are very important for us to realize, this is due to the fact that the autopsy report shows no signs of a sexual assault. Very interestingly, we take interest to the fact that the report mentions nothing about semen on FH's body. If so, it would be mentioned in the autopsy report. At the crime scene, police officers would not have been finding or collecting semen from FH's body. It's important to know that only the MD would be allowed to do that, and we take note of knowing that it would be clearly stated in the autopsy report. So if there was any semen, it would have been somewhere else, but because their was no sexual assault; it leaves us with reasonable doubts as to if there was any at all. Knowing that we know that the news release posted by Cadwrest was issued by an officer at the Chapel Hill Police Station, and he/she is not a Medical Examiner, but together we can brainstorm a dozen reasons why investigators working on this case in 2014, would want the public to take interest in believing what was written in the release as truth. Because FH's clothing had been pulled off, between all of us, we have to believe that the killer staged the crime seen to make it "APPEAR" that a sexual assault had taken place.
According to the lady from CHIPs, there is somesort of DNA profile, but she has been very vague as to it's origin. As far as the note is concerned, if we think very carefully, we should take into consideration that if the killer left DNA on it, then he/she would have left a palm print as well. This would be known as writers palm/hand. If not, it's safe for us to consider realizing that the author of the note could have possibly fisted his/her hand around the pen, and wrote the note without touching the bag. Certainly, it would not be unusual for KR's and FH's finger/hand prints to be on it as well. We should also be careful when we take note to the fact that because the perpetrator took extra time to write the note it could indicate that he/she took comfort in the belief that know one would be coming home to the appartment. Couple this with the fact that the perpetrator was able to leave the appartment without leaving a trace of evidence leading down the stairs, or away from the appartment. This certainly teaches us that he/she wasn't in any kind of a rush.
Therefore, because so much DNA was found, it would be important for CHIPs to locate the foreign DNA in order to find out if it could implicate a suspect.