"This is very much an active investigation," said Philadelphia Police Capt. John Darby of the Special Victims Unit.
Police first brought Regusters in for questioning last week after they executed the first search warrant on the home, police sources said.
She was taken back into custody Thursday after her DNA was found in a mixture of DNA on the shirt the little girl was wearing when she was recovered, police sources said. That and the fact that she worked at an after-school program where the child was enrolled led to her arrest.
It was unclear whether Regusters had given a statement to police, the sources said.
Police have called the taking of the child a "targeted abduction" because the woman in Muslim garb specifically asked for the 5-year-old by name and knew how to evade security at the Bryant school.
Regusters had a preliminary arraignment on the charges Friday and was held on $4 million bail. A preliminary hearing was set for March 6 in Family Court.
Police allege that Regusters is the woman in Muslim garb who is seen on a security video leading the girl from the Bryant school Jan. 14 after posing as the child's mother.
Police allege that Regusters took the child to a home on the 6200 block of Walton Avenue, where police believe the girl was assaulted before being released at a nearby park in Upper Darby. The child was found the next day hiding under a sliding board.
But Regusters' newly hired attorney, W. Fred Harrison Jr., disputed the police assertion: "I don't think it's her. They're different sizes - the woman in the video is larger."
"All I can tell you is that we will test the evidence in court," Harrison added. "I've heard that there's some DNA evidence, but that's about all."
Harrison said Regusters has been in Philadelphia for only about a year and was living with her aunt, Valerie Regusters, and cousins in the Walton Avenue house.
Harrison said Regusters had worked for several months at the day-care center near the Bryant school - where the abducted girl was in an after-school program - but he did not know anything more about Regusters' prior employment or background.
"The family has been cooperative," Harrison added. "They've had their house searched twice, and they've provided DNA. So far, she is the only one charged."
The other three - an adult male, an adult female, and a teenage boy - were released overnight, police said.
There is a $105,000 reward in the case.
The department assembled the Task Force in early February to help members of the Special Victims Unit work the case. It includes six detectives, including several from the Major Crimes Unit.
Sources told The Inquirer last week that detectives had brought in three women from the Walton Avenue house for questioning, taking carpet samples for possible DNA matches, as well as a talking parrot. The bird, a blue and yellow macaw, remains a key piece of evidence in the case, police said. The girl told police that there was a talking bird in the house and she was threatened that it would hurt her if she made too much noise.
But the most valuable clues seem to have come from the young victim herself.
Police praised the girl's courage throughout the investigation. Police have returned to the neighborhood many times with her since the abduction, hoping to jog her memory.
Last week, investigators had the girl walk through the neighborhood with her mother, hoping she would feel more comfortable. That's when the girl recognized the back of the Walton Avenue home. She told investigators her eyes had been covered when she was taken inside the front of the house, but not when she was taken out through the back door in the middle of the night.
Thomas R. Kline, the Center City lawyer representing the girl's mother, said the child's courage was especially notable because the assault caused her "devastating and horrible injuries. She is resilient, just unbelievable.
"The remarkable fact, the single most dramatic fact, is that a brave, precious little girl was able to lead police and investigators through this maze of streets to this location," Kline added.
Kline said the girl attended Bryant, at 6001 Cedar Ave., but was enrolled in an after-school program operated by the Heaven's Little Angels day-care center a block away on South 60th Street.
Typically, Kline said, the girl would be picked up at Bryant by day-care workers and taken to the center. There she would later be picked up by her mother.
Darby has said that there had been prior contact between Regusters and the young victim at the day-care program.
Kline, however, said that neither the girl nor her mother recognized Regusters from the day-care program.
Late Friday afternoon, guardians picking up children at Heaven's Little Angels were mum when asked about the center and Regusters.
The center's front door was locked, and workers let in only parents or guardians. A woman at the door did not acknowledge an Inquirer reporter seeking comment.
At the Walton Avenue house, no one answered the door, and neighbors either declined to comment or said they did not know the Regusterses.
At a West Philadelphia community meeting Friday evening, Capt. David Bellamy, commander of the 18th Police District, told about 40 people that Regusters was not cooperating with detectives, "but scientific evidence will cooperate with us."
Police are continuing to aggressively pursue the criminal investigation, and they welcome any public assistance to help bring the remaining culprits to justice, Bellamy said at White Rock Baptist Church.
"What happened at Bryant is a disgrace," said Novella Williams, a longtime community activist. "Let's make sure this never happens again."
Contact Joseph A. Slobodzian at 215-854-2985, firstname.lastname@example.org, or @joeslobo on Twitter.