Abuser lied on police report

My boyfriend of 6 years was arrested after a DV incident at his family’s home. I’ve lived there for 4+ years and have established residency. Csi took photos of both mine and my little sister’s injuries. The following morning before his arrest, his mom called to make a statement. She claims this was all on footage but never gave up what the ring camera captured. He was released and I was told nothing of his court hearing the next morning. His case was declined due to lack of evidence. I don’t understand how when there was blood drawn, bruising and scratches all over us? His mom’s statement is so full of contradictions and none of our injuries were included in police report! Is this not messed up? Am I able to get the footage subpoenaed if I talk to the DA? I feel so sick to my stomach he got away with assaulting two females. All three of us family members ganged up on me and blatantly lied to police. He also has brothers who are sheriffs!