Are my rights being obstructed

Police conducted a death investigation into a relatives death. Throughout the non criminal investigation they did not speak to any witnesses or family to obtain true and accurate info. They only questioned one non relative of the decedent who had assaulted decedent right before death. Attempts by family and persons with knowledge to inform police were obstructed by detective. Detective refused answer questions stating home surveillance footage would be given to the next of kin at the end of investigation. Upon finally closing investigation detective is now saying the next of kin is unable to have this record but that the owner of the footage may obtain, and now 6 months later have changed their story saying no one outside of the sheriffs office or medical examiner for that district may obtain record - the exemption given to next of kin is :F.S.S 119.071(3)(a) 281.301 Surveillance Video Recordings. Could someone please tell me if and how this exemption applies to to this situatio