Can I use my children's father's new girlfriends background as well as his, to determine visitation?

We have court in February and he wants visitation with his children. We were together 6 years, he has 5+ charges for domestic battery against me, including Child present, intimidation w/ firearm, pointing firearm, criminal confinement, drug charges, and more. We have been separated for over a year, and I still feel like he is too violent for my kids to be around. He was recently charged with Battery on his new girlfriends kids father. She also has charges for drugs. But my main concern is she is a mother of 4 children, she doesn't have custody of all 4. She was also recently pregnant by My children's father and revocated her probation because she failed her drug test for meth. Can I use her charges in court to help against my kids being able to visit them?