Regusters worked at an after-school care program the victim attended, Darby said.
Three other people who were also questioned by police Thursday will be released, Darby said.
"This is the only arrest at this time. The investigation is very much active and ongoing by members of the Special Victims Unit," he said.
Regusters and the three others were taken from a two-story rowhouse on Walton Avenue near 62nd in Cobbs Creek, the same house from which police removed pieces of carpet and a talking parrot during a raid last Friday. Investigators at that time interviewed at least three people from the home and took DNA samples.
The 5-year-old led police to the property after investigators had her retrace the route that she and her abductor took from Bryant Elementary, which is four blocks away. DNA from the child's shirt was connected to something removed from the house, according to news reports.
Thursday's developments came exactly one month after the kindergartner was taken from her class. Police said the girl was taken to a home in the area where she was held for several hours and sexually assaulted. The girl was found the next morning half-clothed in an Upper Darby playground.
"I'm in shock," said neighbor David Hicks, who lives across the street from the home searched by police. "The older guy [being questioned] I've worked with a couple times on music projects. I'm sure there has to be a reasonable explanation . . . I'm pretty sure if he knew anything about it, he would have prevented it."
The older man, whom Hicks identified as Rudy, shared the home with his girlfriend, estimated to be in her 50s, and a teenage grandson, Hicks said. All three were taken in for questioning.
Hicks described the couple as upstanding citizens who have three adult daughters and several grandchildren. Hicks said he had not seen any young children enter the house except for relatives, or any women wearing full Muslim garb.
W. Fred Harrison Jr., who is representing Regusters and the three others who were questioned, told NBC 10: "All my clients insist their innocence. She [Regusters] had no involvement in this as well."
No one answered a Daily News reporter's knock on the door Thursday afternoon as a police cruiser sat outside the home, but a bird could be heard squawking inside. The little girl told police her captors had threatened that a bird would "peck her eyes out" unless she stayed under a bed, reports said.
The crime rattled the city, considering the age of the victim and the breach of security at the school. State Rep. Ronald Waters, D-Philadelphia, whose 191st District includes the school, expressed relief at the news that police seemed to be narrowing in on those responsible.
"I'm so elated because the truth of the matter is that a crime this horrific cannot go without there being some justice," said Waters.
At least $80,000 in reward money - an unusually high sum - was being offered for information leading to a conviction in the abduction, which prompted school district officials to remove the principal and review security procedures districtwide.