A person of interest is in police custody in connection to the killing of a Philadelphia pediatrician found bound at her hands and feet and on fire in the basement of her home.
The man is a 37-year-old exterminator from Levittown, Pa., ABC News station WPVI-TV in Philadelphia reported. He was taken to police headquarters in Philadelphia at about 9:00 p.m. Wednesday.
An arrest could be made as early as today, ABC News sources said Wednesday night.
The developments came after investigators collected hours of surveillance video and canvassed the neighborhood where police Monday found the body of Melissa Ketunuti, 35, a beloved doctor at Children's Hospital of Philadelphia.
A silver Ford truck was towed from the person of interest's Levittown home, which was the same truck spotted on surveillance video Monday in Ketunuti's neighborhood, sources told WPVI.
The man who owns the truck was spotted on video getting out of the vehicle and following Ketunuti to her home. The man left her home after an hour and was seen on video circling her home, sources told WPVI.
Police did not say whether Ketunuti knew the man.
Ketunuti's body was found Monday in the basement of her Graduate Hospital-area row house after her dog walker called 911. Her wrists and ankles were bound behind her back, and she was on fire, police said.
The pediatrician was fully clothed and there were no signs of sexual assault, sources said.
Investigators said she had been strangled with a rope. But they are awaiting the results of an autopsy to determine the cause of death.
With no evidence of forced entry, police wondered whether she knew whoever attacked her.
"We don't know if she walked in on individuals inside of her property," Philadelphia police Capt. James Clark said Wednesday, before police took the person of interest into custody. "We don't know if it's a known doer or an unknown doer."
There was no clear motive, and nothing appeared to have been stolen. Police have questioned Ketunuti's boyfriend, but he has not been declared a suspect.
"We haven't ruled out anyone," Clark said.
The reward for information leading to the arrest and conviction of the person responsible for Ketunuti's death has swelled to $35,000 after community groups contributed money. The total reward includes the $20,000 offered by the city of Philadelphia.
Police have been looking at surveillance tapes from the area hoping to spot the killer and have questioned area residents about what they saw that day.
The culprit will likely be close to home and someone Ketunuti knew, ABC News consultant and former FBI agent Brad Garrett said.
"This is extremely personal. I can't think of anything more heinous or cold to do to another human being," he said.
"The boyfriend can provide all kinds of leads: who she knows, what problems she was having at work."
Ketunuti lived alone on a quiet street and had been there for about three years.
"[She was] super pleasant, really nice," one neighbor said. "Just super friendly."
Ketunuti's hospital issued a statement Tuesday that she was "a warm, caring, earnest, bright young woman with her whole future ahead of her," adding that she will be deeply missed.
"It's going to be just a horrible thing for her family," a neighbor said. "She was just a very nice person, very full of life."