The gunman who opened fire on Friday at a grocery store in Fordyce, Ark., killing four people and hurting 10 others, did not appear to target anyone, officials say, or have any known links to the victims. But the officers in the town of 3,400 who rushed there and eventually subdued the assailant could not have felt more connected.

“They knew everyone personally, from the suspect to the victims on scene,” said Col. Mike Hagar, the director of the Arkansas State Police. He said the officers and deputies were not referring to the victims generically. “They’re calling them by name. They know these people. They’re their friends. They’re their neighbors.” And that, he said, has made this “so personal and so difficult.”

That level of closeness was among the revelations Sunday as the police provided the fullest account yet of what was essentially eight minutes of mayhem. Officers arrived at the Mad Butcher grocery store three minutes after the first shot was fired, then took down the gunman five minutes later.

Four people died: Callie Weems, 23; Roy Sturgis, 50; Shirley Taylor, 62; and Ellen Shrum, 81. An additional person was identified late Saturday as having been injured by the gunman, bringing the total to 10. Of the five people who remained hospitalized, one woman was still in critical condition at a hospital in Little Rock, Mr. Hagar said.

Ms. Weems, who was trained as a nurse, was inside the grocery store. When she saw that someone had been shot, she tended to that person instead of fleeing the store, Mr. Hagar said. Then she was shot herself.

“One of the most selfless acts I’ve ever seen,” he said.

The suspect, Travis Eugene Posey, 44, of nearby New Edinburg, is expected to be charged with four counts of capital murder, which could include the death penalty. It was not clear when he would make his first court appearance, Mr. Hagar said. It was also unclear whether Mr. Posey had legal representation.