Authorities say the victim is a young boy that attended the childcare service run by the wife of 44-year-old Raymond Martin.
Investigators are asking for the public's help as they try to learn more about the baby-sitting service and see if there are other possible victims.
Action News was there on Tuesday evening as Martin was heading back inside his home on Franklin Road in Glassboro, where his wife ran a baby-sitting service called Suebee's Little Angels.
Martin refused to comment after he was charged with sexually assaulting a 4-year-old boy who was in the care of his wife's service.
"First time I'm ever hearing of this," said neighbor John Marshall, "My wife does daycare here also. It's good to know."
Complaints signed last week accuse Martin of aggravated sexual assault and endangering the welfare of a child from an alleged incident on March 30th.
Authorities say they learned of the allegations from the boy's parent.
Neighbors were stunned at the charges.
"It's very surprising," said neighbor Thomas Kerr. "I mean I have two little kids. I live two blocks up. I didn't know at all."
Action News has learned that Martin is a public employee in Glassboro. His $175,000 cash bail was posted. Martin is not allowed unsupervised contact with minors as a condition of his release.
Neighbors speak highly of Martin, adding they hope the allegations aren't true.
"I have nothing but high regard for him and his family," one of those neighbors said.
Action News spoke with Glassboro's mayor, who said we were informing him about the charges. He doesn't know Martin, but still calls the allegations shocking and says the standing protocol in a case like this would be that the accused is suspended pending the outcome of the investigation.
Police ask anyone with information about Suebee's Little Angels or with knowledge of additional possible victims is asked to contact Glassboro Det. Dan Williams at (856) 881-1501 (ext. 88156) or GCPO Det. Stacie Lick at (856) 384-5608.