Pewaukee- Police arrested a 19-year old Pewaukee man after the girls told police they had sex together after meeting on-line.

Karsten W. Koch, has been charged with three felonies for having sex with the two 13-year old girls.

The criminal complaint says that Koch met these girl's on the internet and pursued a relationship with one of them. They met at Frame Park in October and the girl invited him back to her house. At that point Koch is accused of sexually assaulting the girl.

When Koch was arrested he admitted to having sexual contact with the girls.