AKRON, Ohio (AP) — A man suspected of calmly walking into a hospital's intensive care unit and shooting his wife in the head in what may have been a mercy killing appeared perplexed at the attempted murder charge against him when he stood before a judge Tuesday, asking whether his wife was indeed dead.

Hours later, a medical examiner issued a report ruling the woman's death from the gunshot wound a homicide, clearing the way for prosecutors to consider more serious charges in the shooting of his wife of 45 years.

John Wise, 66, with a full white beard, appeared before an Akron Municipal Court judge via video from jail on an aggravated attempted murder charge. His bond was set at $1 million. He is due back for arraignment Wednesday morning.

Wise, who lived with his wife in Massillon, is charged with shooting his wife, Barbara, at her bedside in the ICU unit of Akron General Medical Center on Saturday. The 65-year-old woman died the next morning.

Wise surrendered to hospital security after the shooting and has cooperated with investigators.

A 911 call recording released Tuesday indicates some people at the hospital initially thought the gunshot sound in a patient's room might be an oxygen tank and went in to investigate, only to find a man dressed in black. He was sitting and appeared to be handling a gun.

"We couldn't figure it out. We all went in the room because we thought it came from there. We thought it was an oxygen tank," a woman who reported the shooting told a dispatcher. "Then we saw him sitting there with a gun, and he was like, you know, loading it or whatever."

She said she had gone to hide in a room down the hall but could hear a commotion, with people yelling and running nearby. Then the caller apparently abandoned the call after telling the dispatcher "I think someone's coding or something" and saying she needed to go help.

Another caller from hospital security confirmed to a dispatcher that a patient had been shot.

Wise apparently was confused about the attempted murder charge Tuesday, asking, "Is she not dead?"

Visiting Judge Marvin Shapiro didn't answer his question but said Wise would soon have an attorney who could. "We're going to get you an attorney who will be able to answer all of your questions for you, sir," Shapiro told him.

Messages were left Tuesday with Andrea Whitaker, who was listed as Wise's attorney in court records filed after the court appearance.

Police said Barbara Wise had been in critical condition in the ICU for several days, but details of her illness haven't been made public.

Emergency personnel responded to the Wises' home a week before the shooting for a medical call that involved advanced life support, including oxygen and a heart monitor. Hospital and emergency officials have said they can't disclose any information about patients because of privacy rules.

Akron police Capt. Dan Zampelli said officials are looking into whether Wise shot his wife in a mercy killing.

Wise entered the hospital through the main entrance and went up to his wife's room without drawing any attention, apparently keeping the handgun concealed, hospital spokesman Jim Gosky said.

Hospital security officers ran from the ground floor's emergency department to the ICU's third floor after an alert sounded that someone had a weapon, Gosky said. A distinctive popping sound drew a physician's attention to respond, too.

The Wises lived in Massillon, 25 miles south of Akron. No one has answered the door at their brick bungalow, and messages have been left with family members.

Neighbor Crystal Maxhimer, who lives two houses away, said she knew the couple only in passing. She said she frequently saw them working on their yard together.