Some thoughts (all MOO) on why authorities are taking a while to process the scene...
The house was a "party house," with neighbors reporting that "probably four or five nights a week" they would see people in the windows of the house (
FOX News). Because so many people visited the house, the task of collecting DNA and fingerprints and determining the source of that DNA/prints is made exponentially more complicated. So in addition to the DNA and prints of the three deceased roommates, 2 surviving roommates, and Ethan Chapin (who did not live in house but was staying the night with his girlfriend), there are likely dozens more people whose DNA/prints may be found in the home–– family, friends, boyfriends, hookups, siblings, acquaintances who dropped by during a party, etc.
If authorities are relying on DNA to identify the killer (or at least use DNA to compare against a known suspect), they will be up for a challenge. Anyone who entered the home and touched any surface in that home for more than 2 seconds (
the minimum amount of time required to transfer enough DNA for a full profile) would have left their DNA in the house.
Even if we consider only the surfaces that the killer is most likely to have touched before/during/after the attacks, there will probably be multiple unidentified DNA profiles (either full or partial):
- The sliding glass door in the kitchen and the front door on the first floor will probably have DNA/fingerprints from all the residents of the house as well as any guests/partygoers since they are primary entrances/exits to the house (and from the social media accounts of the victims, it seems the back patio was a common hangout/party spot).
- The bedroom doors of the victims will obviously have the DNA of the occupants, potentially other roommates, as well as maybe friends/boyfriends –– not quite as frequently touched as the sliding glass door and front door, but still significantly more than the average non-college house.
Additionally, I don't think that in this case touch DNA evidence/fingerprints alone will be enough to identify a suspect, let alone convict them. Unlike a non-party house where the occupants would likely be able to provide LE with a list of people who have been in the house in the last month or so, the coming and goings of partygoers would make it extremely difficult (if not impossible) for LE to gather a list of people whose DNA/fingerprints can be expected to be in the house. A good defense attorney would be able to argue at trial that the presence of the defendant's DNA/fingerprints alone is not sufficient to tie him to the crime (i.e., he stopped by a party at the house which is how his DNA/fingerprints got there, not because he was the perpetrator).
IMO the only truly useful DNA in this case for the purpose of prosecution would be blood DNA and touch DNA found on the bodies or on the beds of the victims.
