"I choose not to," Willie Cory Godbolt told the judge when jurors were not in the courtroom.
Godbolt told his defense attorneys later in the day that he had changed his mind and wanted to testify, but the judge would not allow it because that part of the trial had passed.
Godbolt, 37, has pleaded not guilty to four counts of capital murder, four counts of murder, one count of attempted murder, two counts of kidnapping and one count of armed robbery.
Prosecutors wrapped up their case Monday after calling several witnesses over nine days. Defense attorneys called only two witnesses before completing their case.
Closing arguments are set for Tuesday, and the case will then go to the jury.
According to testimony earlier in the trial, Godbolt had gone to his in-laws' home on May 27, 2017, and argued with his estranged wife about their children. Lincoln County deputy sheriff William Durr, Barbara Mitchell, Toccara May and Brenda May were shot to death at that home that night.
Two more people — 18-year-old Jordan Blackwell and 11-year-old Austin Edwards — were killed at a second home in the early hours of May 28, 2017.
Ferral Burage and Sheila Burage, a married couple, were shot to death at a third home a few hours later. Godbolt was arrested near a business as he walked from the Burages' house, investigators said.
Jurors on Sunday were shown video of Godbolt in the hours after he was accused of killing the eight people. In one of the videos, Godbolt said: "I'm completely sorry and heartbroken about that deputy."
Lincoln County sheriff's Deputy Chuck Francis testified that Godbolt spoke to him about Durr shortly after Godbolt's arrest, the Daily Leader reported.
"If the deputy had family, let them know I'm sorry. He was not part of my plan," Francis recalled Godbolt telling him.
Jurors also saw cellphone video of Godbolt sitting in handcuffs, bleeding from a gunshot wound to his right arm.