Story highlights Heather Koon is accused of raping 2 children while working at a day care

Video of alleged rapes found on a sex offender's laptop, day care's attorney says

Koon, 25, was the sex offender's girlfriend, according to CNN affiliate WKYC

Koon passed background checks, the day care's attorney tells CNN

A day care worker in Ohio is accused of raping two of the children she was trusted to care for.

Heather Koon, 25, was arrested Friday at her home in Oberlin and charged with two counts of rape, the Lorain County Sheriff's Office announced in a statement.

Koon was a full-time employee of ABC Kidz Childcare in Elyria from August 2012 to March, according to Carlos Johnson, the day care's attorney.

According to Johnson, authorities inadvertently learned of the alleged rapes late last week when they went to check on a registered sex offender and found an unregistered laptop.

Koon was the sex offender's girlfriend, according to CNN affiliate WKYC

Johnson said the laptop contained videos of the alleged rapes.

He said the day care's administrator called the parents of the two alleged victims on Friday to notify them.

"It's a tragic allegation, and we hope it is untrue," Johnson told CNN.

He added that the day care is fully cooperating with the investigation and that Koon passed both state and federal background checks prior to her employment.

"She was just re-certified in January," he said. Johnson said Koon went to another day care after she left ABC Kidz Childcare.

Calls to Koon's home, the sex offender and to family members of both were not returned Monday night. Koon was in the Lorain County Jail Monday night, according to the sheriff's office website. It is not clear whether Koon has an attorney.

The Lorain County Sheriff's Office said "the case is considered open and active with further investigation to follow."