All of the touching was done on the outside of the children's clothing, Whelan said.
Hochschwender was arraigned on charges of institutional sexual assault, corruption of minors, and indecent assault of persons less than 13 years, and released on $100,000 bail, according to court records. He has been placed on administrative leave, according to the school district.
"We are going to take a look at this case, analyze facts, analyze the law, and we are going to proceed appropriately," said Hochschwender's attorney, Arthur Donato. "He is 54 years old and never been in trouble a day in his life."
According to court documents, Darby Township police contacted county detectives last Thursday for help in interviewing the two 7-year-olds, who said they were assaulted in separate incidents in the classroom in front of other pupils. The teen girl was interviewed Monday.
Hochschwender worked in the Radnor Township School District from 1993 to 2000, according to spokesman Michael Petitti.
A receptionist at Superintendent Stephen D. Butz's office said the Southeast Delco School District would have no comment.
A letter was sent to parents on Friday letting them know of the investigation.
"The district is still investigating, but has not found any evidence to substantiate the reporting to district authorities of the earlier claim made during the time of a previous principal," the district said in a statement.
Efforts to reach School Board President Dorothy Gallagher were not successful.
On the school website, Hochschwender described himself as a teacher for 19 years and father of two sons. "I worked in the mental health field and in construction," he said on the page. "I feel that my life outside of education has given me a unique perspective on life in the classroom."