It was a sexually motivated crime with the murders occurring before the assault(s) could take place, a box cutter was the murder weapon, Abby apparently wasn't redressed AFTER she died, and the sticks were used to cover up the bodies.
All of this can be ascertained from
NM's cross of Dr.PM ....
Motive / Sexual Assault
Q. Fair to say a crime could be sexually motivated, but before the sexual assault occurs, the crime is committed; fair?
A. Could you say that again?
Q. Sure. The crime initially could be sexually motivated, but before any kind of sexual assault occurs, the person kills the victim.
A. Yes.
Q. If the Defendant said that, would that be important information for you to review before you made your analysis?
Murder weapon / Box cutter
Q. Do you know what murder weapon was used to kill the victims?
Q. Did you assume, from the evidence that you saw from the Defense, that it was a knife?
Q. If a knife wasn't used, would that change your interpretation of the crime scene?
Q. What if it was a box cutter?
Victims clothing / Abby dressed BEFORE being killed
Q. Do you agree that A.W., her body is right where she died, it was not moved?
Q. But you're assuming she (AW) was redressed after she died.
(Further) Well, if she got dressed before she (AW) died, there wouldn't be any positioning of the body.
Covering up Crime / Sticks
Q. If the Defendant made a statement that the branches are there intended to cover the bodies, would that change your opinion?