It needs to be said that the jury did NOT actually decide on the DP for CD. The jury made a determination of the facts - whether each murder contained aggravating circumstances by being (a) for remuneration, or (b) especially heinous, capricious, or exceptionally cruel - and then whether there were mitigating factors that would make the application of the death penalty "unjust."
They reported their findings to the court. Yes, and yes, for 3 murders there were aggravating circumstances x 2, and no to the presence of enough mitigating circumstances to matter.
But the actual decision of an application of the DP was then left to the judge, based on the jury's determination of the facts.
------------------
Artis, for LVD, the DP was taken off the table due to misconduct by the state. They were under speedy trial limits with her. The state was given a drop-dead date to submit full disclosure of evidence to the defense in her case, in time to allow her to examine important evidence and ALSO factor in how to work it into both the main trial and also a sentencing phase that comes with a DP possibility.
The the prosec busted past that deadline with more evidence that came later.
The trial at that point could not be delayed without violating her speedy trial rights - to do so would have required them to dismiss the charges on constitutional grounds. At that point there were real questions that the case might have been dismissed, because of violation of her rights to see the evidence and have time to prepare for it.
So Boyce said the state had to take the DP - with its added time-consuming preparation pressures for the defense - off the table, in light of the fact that they were submitting evidence to them much later than the deadline that had been imposed by the court for fairness.
Chad/JP opted to have the evidence that came late, and have plenty of time to consider it. That forced the cases to be tried separately, which Chad wanted. But as a result, the DP stayed on the table for his case.