By J.D. Miles

McKinney (CBSDFW.COM) – The case against Roger Allen Stulce Junior is building and police believe they are dealing with a serial rapist.

On Friday, a third victim came forward with charges against Stulce.

Mckinney Police revealed that Stulce used dating sites to stalk victims and they say that is how he met the third woman.

She came forward after hearing about his arrest last week.

McKinney Police Department Deputy Chief Kim Malolepszy believes the arrest is helping other victims come forward. “Its gotten out in the public arena and we are having victims respond,” said Malolepszy.

Stulce is accused of posing Craigslist advertisements offering women a cheap place to live if they would keep the apartment clean while he traveled for work.

Police say the third assault took place in the same McKinney apartment complex where two others allegedly occurred.

Tenants of the Villas of Eldorado never suspected anything unusual inside the apartment rented by Stulce who lived across town with his parents.

The new charges only add to their shock and disbelief.

“I was really creeped out by the fact that someone could be living here doing that and the fact that nobody knew about it,” said resident Amanda Janczek. “The fact that something like that could happen somewhere quiet like this is weird.”

The latest charge raised Stulce’s bond to $600,000. Police tell CBS 11 News there will likely be a fourth charge at some point in the investigation.