Finally an arrest! Kudos to LE. Still, lots of questions.
It clearly was not an accident, because of the blunt force trauma. What I am less certain about is whether this was first or second degree murder. Because of the shoe left behind, I think Chelsea may have been abducted which suggests that the crime was planned. On the other hand, no murder weapon was used as far as we know. Also, the perpetrator kept clothing/jewelry. He probably wanted to keep these as a souvenir. This tells me that he does not feel guilty, but actually likes to remember what he has done. So there is a "thrill" aspect to this murder. I think he might have committed a similar crime in the future if he hadn't been arrested. Of course, it is possible that he has already committed similar violent crimes that we do not know of.
Were other people involved? I think one article suggested that he acted alone, but are we sure? Whose car did DC drive? His own?
Why were Chelsea's clothes found in Flat Rock? What is his connection to that location? I theorize that perhaps, after Harlin Bird was arrested for making up a fake story, Daniel hid the clothes a stonethrow away from Harlin's residence, to implicate Harlin and to throw off investigators. Another possibility is that Daniel and Chelsea first went to Flat Rock and then to Carleton that night. But this does not seem to make sense because Flat Rock is not on the way. It would perhaps make more sense if another person was involved who lives in that area.
How did Daniel and Chelsea know each other? They probably had several mutual friends. They could have met the first time at the Halloween Party, but I think they may have known each other before. In my research I never came across DC, but he is connected to the same crowd of people. For example, his girl-friend has at least 5 FB friends that I have looked at in the past.