custody battle with CPS slacking

[tandjhelp]

I am a concerned aunt of two neices ages 9 and 6. Recently their parents were arrested for Drunk in Public. The police did a welfare check at 3am 6 days ago and found the children to be alone with no adult supervision. They so far have failed to notify CPS. I had to return children after parents release from jail the next day. Since then my mother has reported to CPS with no reply. She has also filed for custody but is scared of losing. There has been numerous incidents in wich the police have been called on the parents and other cps reports. We do not have a lawyer and was wondering if arrest records and police reports could be obtained by us to use in court. There was a recent EPO on the father in witch it was extended for 2 yrs. The mother has since gotten that lifted. The oldest child actually called 911 in that case. CPS has so far only placed this under advisement and I think it is just going to come down to a custody battle. Do you think if we are able to get the reports that we will have a chance? The children have a rough life where both parents are alcohlics. Any advice would be greatly appreciated.