Justin Garner testified in Moore County Superior Court that he shot Robert Stewart after ordering the man three times to put down his shotgun.
The officer was shot in the leg, but was able to put Stewart in handcuffs. He told the jury Stewart did not put up a fight after being injured, and kept telling him, "Kill me. Kill me, will you just kill me."
The defense admits that Stewart, 47, was the shooter who killed eight people at the Pinelake Health and Rehabilitation Center in Carthage March 29, 2009.
But, Stewart's lawyers say a combination of drugs caused what happened that day. Stewart had been taking Ambien for two years, and 48 hours prior to the shootings, a nurse practitioner had prescribed Stewart an anti-depressant and Xanax.
Prosecutors say Stewart knew what he was doing and are seeking the death penalty.
Stewart's estranged wife worked at the nursing home at the time of the shootings. Wanda Luck managed to hide in a bathroom in a locked area for Alzheimer's patients and was not injured in the attack.