CHICAGO (WLS) -- A woman claiming a teacher sexually abused her mentally disabled daughter is now suing the Chinatown day care center.The teacher, Jian Feng, has been in jail without bond since January of 2015 on sexual assault charges.He pleaded not guilty.The abuse reportedly happened between November of 2014 and January of 2015 at the Easter Seals National Teachers Academy.The suit claims the center hired an "overly aggressive individual" and did not protect students.Feng, 25, who taught preschool, was arrested and charged with four counts of predatory criminal sexual assault after he allegedly molested two girls under 3 years old under his care, police said.Prosecutors say Feng, who has a degree in early childhood education, molested the girls on multiple occasions, including one incident allegedly caught on video. Investigators say they have surveillance video that shows Feng inappropriately touching one of the girls while she was sleeping.Investigators say Feng told police he did it because he was curious and because his brain made him do it."He was removed from the location and will have no contact with children at Easters Seals Metropolitan Chicago. Our first priority is the care and safety of our children. We conduct our background checks in strict conformity with federal, state and local guidelines," an Easter Seals spokesperson said at the time.Feng is being held without bond.