Prosecutors say the aide, Alfred Dean, 76, of Chesilhurst, faces charges of Aggravated Sexual Assault, three counts of Sexual Assault and Endangering the Welfare of a Child.
Authorities filed charges against Dean Tuesday and he is in police custody.
The child's family reported that Dean's assaults happened on a van transporting children for the Waterford School District while other students were on the vehicle.
After the report to Dean's employer, T&L Transportation, the company called law enforcement and Dean was arrested the same day.
Furious parents attended a meeting inside the library of the Waterford Township Elementary School Wednesday night, demanding answers.
"Do you know what it felt like, as a parent, knowing my daughter was riding home, that she could be in danger, and I wasn't given the option to protect her?" one woman said.
Some parents wanted to know if Dean was an aide on their child's bus. It's information, parents said, the district and prosecutors were unwilling to give.
"You called a meeting that said it's a crisis, you have all these people here guessing 'Was it my bus?'" said another parent. "That's not fair."
Action News spoke to one father who believes his 4-year-old daughter was a victim.
"You show me how he touched you," the father said, recounting the conversation with his daughter. "She grabbed, if you want to call them, breasts, and groped me as a male would grope a female."
"How could she make that up?" he added.
As an aide on the bus, which transported some special needs students, Dean would have been one of two adults on board at all times, suggesting it wasn't just children who witnessed the alleged acts, but the driver as well.
Investigators won't say if there was a camera on board, but some parents insist there was.
School officials say they're limited to what they can say as prosecutors continue to investigate.
"We understand that folks are going to be angry. It's understandable and we respect that anger," said Waterford Superintendent Gary Dentino. "But what's first and foremost is that the investigation is able to proceed without compromise."
Police want to know if any other children were assaulted by Dean . Anyone with information is asked to call the Camden County Prosecutor's Office at (856) 580-6061 or Waterford Police at (856) 767-2134 ex. 519.
Action News learned Dean was hospitalized Wednesday night for an unknown reason.
