Investigators are examining a car and chasing leads in an effort to find a Bucks County woman and her 9-year-old daughter whose disappearance is being treated as a double kidnapping by authorities.

One question they are expected to ask is why the girl, Julia Rakoczy, was withdrawn from one school on May 1, and enrolled in another.

Julia's mother, Bonnie Sweeten, 38, called 911 yesterday saying she was in the trunk of car and that she and her daughter had been kidnapped by two men following a fender bender in Upper Southampton.

This morning, as Julia's father appealed on national television for the release of his daughter and ex-wife this morning, FBI Special Agent J.J. Klaver said investigators were following a number of leads in the case. He did not elaborate.

Anthony Racoczy said that he and Bonnie Sweeten had maintained a good relationship since they divorced in 2003, and that he knew no reason for anyone to harm her or their daughter.

"I'm still in shock," he said on NBC's Today show. "She's a great mother."

Earlier, Philadelphia police located Sweeten's SUV in Center City.

The discovery came nearly 12 hours after Sweeten made a desperate sounding 911 call, during which she said her daughter was still in the family's Yukon Denali.

A police officer spotted the SUV about 1:30 a.m. at 15th and Chestnut Streets in Center City, two blocks from the cell phone tower that picked up Sweeten's call, police said. A parking ticket was on the windshied.

Investigators hope the car will yield some clues.

When Sweeten, 38, called police shortly before 2 p.m. yesterday, she said she was in the trunk of a dark-colored 1990s Cadillac.

The mother reported she and daughter were taken by two black men after they were involved in a minor accident with the Cadillac on Street Road in Upper Southampton Township, about a mile north of the city, Klaver said.

Police found nothing at the scene and investigators appealed for help from any possible witnesses.

Police also impounded a black Cadillac with front end damage in Hunting Park last night, but the FBI indicated it was not linked to the investigation.

Julia is described an Amber Alert issued last night as 4-feet, 1-inch tall, 59 pounds, with long brown hair, blue eyes, and a dime-sized birthmark on her forehead.

She attended the Belmont Hills Elementary School in Bensalem, but Susan Phy, spokeswoman for the Bensalem School District, said the girl was "withdrawn" from the school on May 1.

Julia Rakoczy and her sister Paige enrolled in the Neshaminy School District in Bucks County about one month ago, said Louis T. Muenker, district superintendent. Muenker declined to identify which schools the sisters attend.

Crisis intervention teams were sent out to district schools to help faculty and students handle the news, Muenker said. Letters also were sent home to parents.

"What we're trying to do is to have a sincere hope that everything is fine for this family," Muenker said. He declined to coment further.

Phy said the Bensalem district would have no further comment.

"She loves the Phillies. She plays softball. She always dances around the house," her father said.

Her mother is described as 5-feet, 11-inches tall, 130 pounds, with blond hair and blue eyes.

Anthony Rakoczy and Sweeten were divorced in Bucks County Court in May 2003. Online court records indicate no ongoing disputes or court actions since the decree was granted.

This morning, Rakoczy said that when he was told of the 911 call, "I was thinking that this is not real, that this is stuff you see on TV." He described Sweeten as very organized, on top of her children's many activities, and as someone with no known enemies.

"I don't understand why anyone would want to keep them," he said. "Just let them go."

Sweeten has since remarried to Richard Sweeten, who operates a landscaping service. According to her Facebook page, she has three daughters, and is a 1989 graduate of Bensalem High School."

Her older daughter, Paige, 15, wrote on her Facebook page: "im asking everyone, to please pray for my mom and sister pray please."

A parent of a child who attended school with Julia said that Sweeten had been very active at the school. The parent, who asked not to be identified, said news of the kidnapping broke before a student performance at the school last night.

"The word spread quickly and no one knew what to say," the parent said. "Everyone is shocked. We just pray they come back home safely and we can see them once again in the school she so generously shares her time with."

Anyone with information about the case was urged to call 911.