Authorities ruled out murder-suicide in the deaths of a couple and their paralyzed 20-year-old son, and said the father was able to call 911 and talked to police before he died.

William Fowler, 53; his wife, Estella, 50; and their son John, injured in an auto accident several years ago, were found shot in the living room of their home early Sunday, police said.

The father called 911 just after 1 a.m., and he later talked to the arriving officers, Detective Patrick Mangold said Monday. He was pronounced dead later at a hospital; the other two victims were dead at the scene, authorities said.

Mangold declined to give details on what the dispatcher or the officers learned from the dying man, adding that investigators were still trying to determine exactly what Fowler had said because it was hard to hear him.

Police have several possible suspects, but have not narrowed it down, Mangold said. Murder-suicide was ruled out, he said.

Each victim had been shot several times, but there was no sign of forced entry and the row house did not appear to be ransacked, authorities said.

"We are investigating whether this was done for monetary reasons, but we don't yet know," Homicide Sgt. Robert Kuhlmeier said Sunday. "We are looking to see if something was stolen."

The couple had been caring for their son since he was injured in an auto accident about four years ago, police said. The mother also had been seriously ill, and her husband had recently left his job to care for his family, police said.

Elizabeth Fowler, 24, the wife of one of the couple's two other sons, Robert, remembered John Fowler as being in good spirits despite his condition.

Nothing was more important to the Fowlers than caring for John, she said.

"They were just such a close family," she said. "They centered their life around him. They were sweet, helpless people."