According to TMZ, police initially responded to a call about a disturbance in Hiltz's apartment.
Once they looked into the situation, the officers made the decision to arrest the 32-year-old actress and place her child into protective custody.
Hiltz was taken to a nearby station where she was booked on suspicion of misdemeanor child neglect. She has since been released from custody.
Her lawyer is reported as saying, "It was an unfortunate misunderstanding. No charges have been filed and absolutely no harm was done to the child."