With the jury outside the courtroom, Sierra told the judge, “I do not wish to testify.” Sierra, 42, has confessed to killing Gladys Machado, 29, and her daughters, Julia Padrino, 6, and Daniela Padrino, 3.

The defense rested after calling corrections consultant Raul Banasco, who described differences between life without parole and death row. Banasco said people serving life sentences may work in prison kitchens or laundries, while death-row prisoners do not have to work and face tighter security and more limited interaction with other inmates.

He described death-row cells as measuring 6 by 9 feet, with a bed, toilet and television. Prisoners are permitted outside their cells 20 hours a week, including six hours in a recreation yard, and can receive visits and use a tablet to communicate with family and friends, he testified. Banasco also said Sierra would receive medical care for his Type 1 diabetes under either sentence.

Prosecutors began presenting rebuttal evidence Thursday, including testimony from clinical neuropsychologist Robert Denney. Denney said he evaluated Sierra in person on Aug. 26 and testified that Sierra performed better on memory tests than groups with moderate to severe traumatic brain injuries. He said the results suggested Sierra overstated memory problems in his self-report.

The defense had asked jurors to consider an expert’s assessment that a childhood car crash had affected Sierra’s executive functioning. Denney characterized those skills as at least low-average and said Sierra scored above average on maze tests.

The penalty-phase jury will weigh the evidence as it considers whether to recommend death or life in prison. The trial account did not report a recommendation or final sentence.