A Marietta softball coach is locked up, charged with sexually assaulting a girl he was training.

Isuru "Ian" Perera, 31, is charged with cruelty to children, aggravated sodomy, sexual battery, aggravated sexual battery, computer pornography, and distribution of obscene material.

"He is a coach/trainer at the Champions Fast Pitch Softball complex," says Marietta Police Officer David Baldwin.

According to investigators, the victim -- who was 16 when the assaults began -- was being trained by Perera and he used his position of authority to commit his crimes.

"Over the period of time," Baldwin tells WSB, "he used his position to coerce and intimidate her into committing numerous sexual acts against her. All of these sexualy assaults occurred inside his office at the complex."

Perera is being held without bond at the Cobb County jail.  Now, police are looking into whether there may be other victims.

"That's our biggest concern," says Baldwin, "that there are girls out there who are too ashamed of what happened to come forward."

Anyone with information should contact Marietta Police Detective Moeller at 770-794-2366.