Small said there was no sign of forced entry at Ketunuti's Graduate Hospital-area rowhouse, on a well-maintained street blocks from Rittenhouse Square. She was discovered around 12:30 p.m. by her dog walker, police sources said, who showed up to walk Ketunuti's pit bull/Lab mix, Pooch, and found the door unlocked and the body smoldering facedown in the unfinished basement. The burns were concentrated on her face and chest, Small said.
"The Fire Department actually had to put her out," Small said.
There were no immediate signs of sexual assault, police said.
The motive for her slaying remained under investigation, with police knocking on doors and combing the neighborhood for surveillance footage. Small said that there were no signs of a struggle in the house and that he did not believe anything was taken, though other sources said her purse may be missing.
Police are looking into whether she could have been followed home after running errands at nearby stores, but Small acknowledged Monday that it was possible she knew her killer.
"We're not sure exactly what happened," Small said. "We're not sure if it was a burglary or a robbery. We don't know."
Ketunuti wrote a blog for several years detailing her long-distance runs and her studies in hospitals around the country. Her mother is from Belgium, and her father was listed as a civil engineering consultant in Bangkok, Thailand, on a blog he used to keep.
Having earned a doctorate in medicine from Stanford University, Ketunuti had considered working as a surgeon internationally. In the summer of 2005, she worked on an AIDS research fellowship in Botswana through the National Institutes of Health. She also completed internships at Johns Hopkins Hospital and New York University.
While at Stanford, she wrote of 18-mile weekend morning runs along trails bordering the San Francisco Bay.
"This run will definitely be on the 'to do' list for the future, when I'll have forgotten about the sinking mud, grueling hills, and disgusting bugs," she wrote after one such day. "Already almost a week has passed and I'm telling myself that really, it wasn't that bad. Sure, my foot got stuck in the mud and my socks were completely soaked, but how many people have actually looked down on the Golden Gate bridge?"
Ketunuti, a petite woman with brown hair and brown eyes, was an avid traveler and wrote of expeditions to African wildlife preserves, mountaineering in California, and fishing trips off the coast of Mozambique.
After receiving her doctorate in medicine, she completed a surgery internship at Georgetown University Hospital and a second internship, performing cardiothoracic surgery at a veterans hospital. She moved to Philadelphia in May 2008. That October, she began a pediatrics residency program at Children's.
"The CHOP pediatrics program, aside from being one of the largest in the country (40 something residents per year), is an incredibly supportive program," she wrote. "As sexy as it was to be a life-saving surgeon, I feel much better suited for pediatrics."
Shortly after moving to Philadelphia, she visited her parents in Bangkok. It was her first time back in three years, and she was excited to return, writing that the city hadn't changed as much as she had expected. "The taxis are a different color, the airport has free Wi-Fi . . . but the city still has that same sense of disarray with its millions of people."
During the trip, she wrote, she and her mother toured the city's bustling outdoor markets in search of decorations for her new apartment.
Neighbors in Center City were stunned and deeply unsettled by the news Monday, and as detectives spent hours going in and out of Ketunuti's house, they stood by, talking among themselves. Most said they did not know the victim well but described her as a pleasant neighbor who was often seen walking her dog. She had lived there for about three years, neighbor Victor Pisani said.
"A nice girl," he said. "I don't understand it."
Another neighbor, who declined to give his name, said he came outside when he heard the firefighters arrive. He knew something was wrong when he saw them leave the house, he said.
"They looked shell-shocked," he said.
Contact Allison Steele at 215-854-2641 or firstname.lastname@example.org.