No arrests had been made in the Monday death of Dr. Melissa Ketunuti, 35, ABC News reported Wednesday.
The body of Ketunuti, a pediatrician at Children's Hospital of Philadelphia who lived alone, was discovered by her dog walker. Police said the doctor's wrists and ankles were bound behind her back, there was a rope around her neck and she was on fire, investigators said.
An autopsy was being performed to determine whether strangulation was the cause of death.
There was no sign of forced entry or indication of theft or any other motive, police said.
"We don't know if she walked in on individuals inside of her property," city police Capt. James Clark said. "We don't know if it's a known doer or an unknown doer."
Police questioned Ketunuti's boyfriend but had not named him a suspect, ABC said.