Yes, this would have been after she came home from FL, but before he confessed. Remember, Jessica was 'missing' for 5 days. This obviously happened right in there, probably day 1 or 2.
Regarding the fears that GG will prevail in this case: I really don't know how anyone could think any attorney, even the most "high-powered" one is going to get this guy off where he walks out a free man. It's not going to happen. They have him on video doing the deed. That's direct evidence, the "smoking gun." He confessed. That's direct evidence. And then all the circumstantial evidence, blood, hair, fibers, the body.
Even if the attorney attempts to blame everyone else in GG's life, nothing in the law justifies 1st degree premeditated murder. His life wasn't in danger, so no self-defense. He's not legally insane, as he clearly knew right from wrong, knew he was committing crimes and tried to cover it up. It was premeditated, so he can't claim a fight broke out and oops (which would have been needed for a lesser 2nd degree charge).
This guy is toast. This will not be an OJ outcome, GG is not some celebrity, there's nothing racial for an attorney to play on. GG will never walk free no matter what he or his attorney attempt.