The ex-wife of a gunman accused of killing eight people in a nursing home said he had "violent tendencies," and police said he could have killed more if a heroic officer hadn't intervened by shooting him.

Police said Robert Stewart, 45, went on a terrifying rampage in the Pinelake Health and Rehab center on Sunday morning, killing seven residents and a nurse and wounding three others, including the officer. But witnesses told police Stewart left some people untouched during the massacre without explanation.

Authorities wouldn't discuss Stewart's motive late Sunday, but law enforcement officials said they would release more details at a news conference Monday. Stewart was in custody, but authorities would not give any details about his injuries or treatment.

Stewart's ex-wife, Sue Griffin, said she had no idea why her ex-husband would target the facility or whether he had any connection to it.

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She said Stewart had been recently reaching out to family members, telling them he had cancer and was preparing for a long trip and to "go away."

Griffin said she was married to Stewart for 15 years, and while they hadn't spoken since divorcing in 2001, he had been trying to reach her during the past week through her son, mother, sister and grandmother.

"He did have some violent tendencies from time to time," Griffin said.

Officials said the shooting could have been bloodier if 25-year-old Carthage Police Officer Justin Garner hadn't wounded Stewart while trading gunfire in a hallway. Garner was wounded in the leg.

"He acted in nothing short of a heroic way today, and but for his actions, we certainly could have had a worse tragedy," said Moore County District Attorney Maureen Krueger.

Stewart is charged with eight counts of first-degree murder and a charge of felony assault of a law enforcement officer. Authorities offered few other details, allowing only that Stewart was not a patient or an employee at the nursing home and isn't believed to be related to any of the victims.

Beverly McNeill said her mother, Pinelake resident Ellery Chisholm, called moments after the gunman stormed into her room and pointed his "deer gun" at her roommate. "They're up here shooting, they're up here shooting," Chisholm frantically told her 14-year-old granddaughter, Tavia, over the phone, McNeil said.

Chisholm told her daughter that she hid her face in her shirt so she couldn't see the man or what she expected him to do, McNeill said. He didn't shoot, but left the room and began shooting down the hallway.

The small town about 60 miles southwest of Raleigh in North Carolina's Sandhills region was shocked by the violence.

"I don't know if the emotion entirely has set in," said Police Chief Chris McKenzie, a Carthage native who said nothing in his nearly 20-year law enforcement career compared to Sunday's slaughter. "It's a small community built on faith, and faith will get us through."

Krueger said the victims were Pinelake residents Tessie Garner, 88; Lillian Dunn, 89; Jessie Musser, 88; Bessie Hendrick, 78; John Goldston, 78; Margaret Johnson, 89; Louise Decker, 98; and nurse Jerry Avent, whose age wasn't immediately available.

Friends and family of Pinelake residents and employees started to gather not long after the shooting at the First Baptist Church of Carthage. They were frustrated by the lack of immediate news about who had died, said Lea Chandler, a volunteer with the Moore County chapter of the American Red Cross.

Chandler said she saw two women and their husbands get the news that their mother had been killed.

"They were just crying out, 'Why mama?"' Chandler said. "To see people suffer is hard. To see people suffering, not knowing, trying to find information."

The facility was closed after the attack as authorities worked to gather evidence inside and out. Krueger declined to say if authorities had moved the surviving residents from the 110-bed facility, including patients with Alzheimer's disease, saying only, "They're safe, which is the primary thing."

Among the items investigators found was a camouflaged-colored rifle or shotgun, which was leaning against the side of a Jeep Cherokee in the parking lot.

Sunday's rampage happened just weeks after a man killed 10 people, including his mother and several other relatives, in the worst mass shooting in Alabama's history on March 10. On March 11, a teen killed 12 people at his former high school in Germany.