Charges were dismissed Thursday against a retired teacher and foster parent accused of sexually abusing a child in his care.

Frank Spryszak, an assistant county prosecutor, asked Lucas County Common Pleas Judge Ruth Ann Franks to dismiss one count of rape and two counts of gross sexual imposition against Robert Koenig, 63, of Toledo.

He told the court that new evidence had come to light recently “that put us in a position that we no longer felt that we had sufficient evidence to proceed to trial.”

Defense attorney Lorin Zaner said Mr. Koenig was extremely relieved. He and his wife, Bettie Koenig, had been foster parents for Lucas County Children Services for about five years after Mr. Koenig retired from Toledo Public Schools, where he had taught from 1975 to 2010.

The couple withdrew their license to be foster parents when the allegations were made and do not intend to be foster parents again, Mr. Zaner said.

“They truly had a desire to help children,” he said. “To be in a position of being falsely accused because you put yourself out there to help children is a tragedy because these are good people. Their names are drug through the mud. Why do you want to put yourself in that position? It’s terrible.”

He thanked Mr. Spryszak and the prosecutor’s office for “doing the right thing” after inconsistencies were found in statements made by the alleged victim and other problems became apparent.

A trial was set for Sept. 28.

“We had the documentation to show that there’s no way our guy could’ve done what they said,” Mr. Zaner said.

Mr. Spryszak said prosecutors as much as defense attorneys have a duty and obligation to seek justice.

“If we do not feel we have enough evidence to go forward, we can’t force a case to trial if we can’t prove it,” he said.

— Jennifer Feehan

First Published September 18, 2015, 4:00 a.m.