The deliberations required 12 jurors and four alternates to remain sequestered in Floyd County an additional night after they recommended Tuesday that Gibson be executed for the April 2012 slaying of Christine Whitis, 75, of nearby Clarksville, The Courier-Journal reported.
Defense attorney Patrick Biggs called the extended deliberations the "overkill phase of the trial."
"He sits over there as a condemned man and now they want to pile on more years," Biggs said.
Deputy prosecutor Steve Owen agreed that if Gibson, 55, of New Albany, is executed, the additional prison sentence would have no meaning.
"But the death penalty hasn't been implemented," he told jurors.
Floyd County Judge Susan Orth is bound by law to follow the jury's death-penalty recommendation. She has scheduled Gibson's sentencing for Nov. 26.
During the murder trial, the jury wasn't allowed to hear of Gibson's nine prior unrelated felony convictions for assault, wanton endangerment, robbery, sexual abuse, auto theft and other charges in Kentucky and Indiana between 1992 and 2007.
Orth instructed jurors that to be convicted as a habitual offender, they had to find he was convicted of at least two separate prior felonies.
The jury of eight women and four men was brought in from Dearborn County, about 100 miles away, because of pretrial publicity surrounding Gibson.
Gibson still faces murder trials in connection with the slayings of two other women: Stephanie Kirk, 35, Charlestown, who was found buried in Gibson's backyard days after Whitis' body was found, and Karen Hodella, 45, of Port Orange, Fla., whose body was found in the Ohio River in 2003. Gibson also faces the death penalty if convicted in Kirk's death. His trials for those cases are scheduled to begin in January.