Is this child abuse from a legal standpoint?

My 9 yo daughter asked me to scratch her back and told me to avoid the bruised area when she came back from her father’s house last week. I asked her what happened and she told me that while she was yelling at her 2-yo brother, that her dad picked her up and put her in her room in front of her dresser. He was angry, and put her down so hard that the knob on the dresser left a large bruise on her back. I asked him about this and he said that was what happened, and justified his behavior because she was being mean to her brother and had to stop her.

I took a picture of the bruise and will be showing the picture to my daughter’s counselor (daughter has already told counselor she is afraid of her father). What else should I do?

I am not sure your ex’s behavior rises to the level of abuse, however if this type of behavior becomes regular, it may. If and when you do go to court for custody, the picture, and if necessary, the counselor’s testimony may be used to inform the court of a potential danger your ex poses to the children.