Ok we have been to this apt now 3 different times with the police and they still make my daughter leave without her baby. Plus this boys sister interfers and will not let my daughter take the baby. I am really at my wits in with this and really don't know how to go about to get my grandson from this dead beat dad

Does the dad have a custody order awarding him sole custody?

It sounds like that might be the case. The police won't interfere with a court order like that.

You can file to try to get legal custody of the child. But you HAVE to do it through the court system.