Yes, but the jury won't ever see the note. It'll be intersting to see how McNeill manages to plant the suicide seed when he presents the defense.
The only seed I see is the state of mind angle. Even then, the wound to the throat was only minor... suicide highly unlikely even with state of mind. I guess they could claim she 'might' have tried to commit suicide and fell, busted her head, and died. Then Cesar just 'panicked', buried her and fled.