I ask this with no snark - how much time and energy do you think LE is putting toward this case at this point? They have a bad guy in jail. Not for AJ's death, but they have him. Theoretically, no one else is talking, or if they have, their information did not lead to further charges against anyone. The additional person or persons is keeping very still and quiet, thankful that this is fading away. AJ's friends and family have resumed their lives and are beginning to cope with the loss of their loved one. Granted, I live far away, but I do not see/hear anyone pressuring LE or legal to press charges, name a POI, or keep looking. Perhaps people believe or want others to believe that the right and only offender is in jail, albeit not for AJ's death.
So, I really don't know how cases like this go and I ask with sincerity - how much effort is being put towards a case like this? Is LE just waiting for someone to say something new? Could be a very long wait.