A disturbing case of sexual assault on children at a popular amusement park came to light Monday.
The incident happened in a swimming area at the park. Police said he did not know his victims.
Police say Gramatzki, who also goes by Frederick Stein, was caught touching and groping three girls ages 10, 15 and 17.
Park security officers detained Gramatzki that night until police arrived and placed him under arrest.
Gramatzki faces two felony counts of child molestation and one count of battery.
His first court appearance isn't until next Tuesday.
The Santa Clara Police Department are still looking for witnesses who may have seen Gramatzki at Great America or who have any information about him that would help their case.
They are asking people to call Detective Sergeant Craig Middlekauff at 408-615-4823.