I agree - I sense a victim blaming defense in the works especially if her blood is on the clothing found (Link upthread) and the gun they found is the murder weapon. IMO.
I just can't think of anything they could credibly say about her that would justify him shooting her multiple times and leaving her body there, driving off without a scratch on him, not calling 911 or contacting law enforcement, and then posting and retweeting inane things on Twitter as if nothing had happened. They have to say he didn't shoot her. They can't argue that he had a good reason to do it.
I think the only plausible legal strategy is to try to discredit every bit of forensic evidence and anything that BT may have said while in custody to get all that excluded from trial, and then throw out some theory about an unknown killer. They have to go after the investigators, saying they focused exclusively on BT instead of looking for the "real killer", question how the evidence was collected and handled, and all the other defense attorney tricks for defending clients who clearly are guilty if all the evidence is allowed.