Geraldine McIntyre would sit outside in her rocking chair, waving and smiling at passersby who said a friendly “Hi, Miss Geraldine!” when they spotted her. The 71-year-old, who used a walker or wheelchair to get around, felt safe in her Capitol Heights neighborhood; in the summer, neighbors said, she would sometimes leave her door open so people delivering her meals could come in.

About 3 p.m. Saturday, though, someone asked police to check on McIntyre, and officers found her fatally wounded inside her home on Chapel Oaks Drive. She was pronounced dead at a hospital a short time later. Now, Prince George’s County detectives are trying to determine who would want to kill a sweet, elderly woman with limited ability to defend herself.

“What happened to her — she didn’t deserve that,” said Robin Washington, 49, who lives down the street. “I just hope that they catch whoever did it.”

On Monday, crime scene tape still surrounded McIntyre’s modest, yellow-sided house with a winding, wooden ramp leading to its front door. For the second day in a row, homicide detectives fanned out across the neighborhood, distributing fliers as they asked anxious residents whether they might have noticed anything unusual over the past several days.

So far, police seem to know little about what led to McIntyre’s slaying. Police said they are searching for a “possible suspect,” but they released only a nebulous description.

Law enforcement officials, speaking on the condition of anonymity because they could be disciplined for candidly discussing an ongoing case, said McIntyre was stabbed to death, and detectives were exploring whether the slaying might have occurred during a break-in or robbery. The officials said the investigation was still in its infancy, and few possibilities had been ruled out.

Neighbors said McIntyre lived with an adult daughter, but the daughter had been hospitalized before her mother was found dead. Both McIntyre and her daughter, neighbors said, had limited mobility. McIntyre, they said, used a wheelchair or walker to get around, and her daughter was either bedridden or used a wheelchair.

One neighbor, who declined to give her name to protect her privacy and safety, said those facts made the case even more unsettling. She said McIntyre was a “sweet woman” who would pose no threat to an intruder.

“First off, she was elderly. Second off, she was handicapped,” the neighbor said. “To do that [to her], you had to be sick in the mind.”

Efforts to reach McIntyre’s family members were largely unsuccessful; a man who identified himself as McIntyre’s nephew said another relative would have to call a reporter back at another time.

Staff researcher Magda Jean-Louis contributed to this report.