This case has so many questions left unanswered.
Since Judge Deering has not taken the death penalty out of the equation 100%, I really don't know if, or how we can get a true answer as to who will decide sentencing.

Snipped:
"Then, contrary to what many think,
judges, and not juries, almost always determine sentencing for a convicted criminal defendant (although a few states still reserve the choice of sentence for the jury). It is pretty common for the judge to tell the jury not to consider punishment when determining whether a criminal defendant is guilty or not guilty. Indeed, a mistrial could be declared if it becomes known that the jury considered punishment when determining guilt."
However, there are also some special occasions that require a jury to weigh in on a convicted criminal's punishment. For example, in some states' rules for capital punishment cases (
death penalty cases), judges are not permitted to impose the death penalty without the agreement of the jury."
Sentencing Law FAQ - FindLaw