By Walt Hunter, Natasha Brown

PHILADELPHIA (CBS) - The Ben Franklin Parkway, gateway to Center City along with art and cultural centers, was the scene of a vicious crime early Wednesday morning.

Police say Warren Fitts, a career criminal with 25 arrests going back more than two decades, attacked a 28-year-old graduate student, ripping off her clothes and raping her on the street.

Investigators say the student, who had recently moved into the area, had been drinking heavily, and lay unconscious when Fitts allegedly assaulted her.

A security guard in a nearby building spotted the attack and called police who raced to the scene, immediately arresting Fitts.

“I saw that the female was unresponsive and the male was intoxicated as well. Got him off of her. He tried to run down the parkway maybe 50 to 100 feet, so I chased him and held him for police,” said Charlton Lane.

The victim was taken to Hahnemann Hospital and later released.

Sources tell CBS 3 that Fitts is also being investigated as a possible suspect in several sexual assaults of women who leave Center City bars.

Police are going through records of past attacks and using DNA analysis to determine if additional charges will be filed against Fitts.