The announcement of the reward came on the same day police released surveillance video of the incident.
Police say Tuesday at 3:50 p.m., while walking home from the store with her 2-year-old brother, an unknown male followed them in an older 4-door white vehicle.
The male parked his vehicle on the corner of Porter and Lee streets, exited the vehicle, and followed them onto Lee Street.
Authorities say the suspect then put his hand over the girl's mouth and attempted to carry her away.
The girl struggled with the suspect and then fell as the brother watched nearby.
Initial reports say the girl bit the suspect on the hand.
Officials say the suspect then fled in his vehicle east on Porter Street.
The suspect is described as an Hispanic male, 5'9-6' tall, medium complexion, thin build, 30-40 years of age, with a thin moustache and short black curly hair. He was wearing a black short sleeve T-shirt and blue pants.
His vehicle is described as a late 1990's to early 2000's white mid-sized foreign 4-door car, possibly a Mitsubishi or Nissan, with a black scuff mark on the driver's side rear bumper and a dent on the left front fender wheel well.
Anyone who sees the suspect or the vehicle is asked to call 911 or contact the Special Victims Unit at 215-685-3251.
At the Wednesday afternoon news conference, Mayor Nutter said he's never seen a video like this one.
"Our children must be able to walk around their own neighborhood without lowlifes like this individual coming up and grabbing them, touching them, or doing anything else. It's completely unacceptable, totally outrageous, we need the public's help," Nutter said.
Police say the girl had been swimming with her 13-year-old sister earlier that afternoon at the city recreation pool at 3rd and Shunk streets.
The victim's father and mother say the child was traumatized by her ordeal, but otherwise not injured.
The father tells Action News that he warns his children all the time about these types of incidents and apparently it paid off, because his little girl scared that would-be kidnapper away.
Now they just want him off the streets before he tries to grab another child.