Timothy Loehmann shot Tamir Rice, who was playing in a playground with a toy gun that fired pellets.

The streets were calm Sunday after police arrested dozens of demonstrators when protests grew increasingly aggressive in the wake of a patrolman's acquittal in the deaths of two unarmed black suspects.

The family of 12-year-old Tamir Rice, who was shot and killed by a Cleveland police officer, says they are frustrated with the now six-month investigation in the fatal shooting.