If it weren't so serious,it would be laughable. It is more than curious that all were eliminated and one was fingered SO RAPIDLY !!!!!!
I may be naive, but I can't imagine a responsible team of investigators willing to give the quick glance treatment to the "friends" of Damon and Brenda. It is illogical, questionable and unusual.
If nothing else, they should have wanted to nail down details of the hours preceding the crime and verify a number of stories. How could they possibly be convinced that the perp acted alone or that other people had not contributed; perhaps even unwittingly?