Translation of "Beatin" in German

When we came up on Juniper's room, there was this guy in there, he was beatin' up on her.
In Junipers Zimmer war ein Kerl, der sie verprügelt hat.
OpenSubtitles v2018

This guy was beatin' on his old lady, so I took upon myself to end the dispute.
Er hat seine Alte verprügelt und ich wollte den Streit beenden.
OpenSubtitles v2018