In 1995, I tried to involve myself with the detectives of the Keller, Texas PD in the death of my buddy. I was threatened with arrest if I attempted to show up at the Keller PD station.
Four months later I got a interview with the Tarrant County ADA and her investigator and presented a piece of evidence that I found in the middle of their crime scene after the house was released back to his wife.
Her Professional investigator was able to use the evidence to build a Capital Murder case which was successfull in prosecution.
The four Keller, Texas PD detectives were not invited to the trial due to neither the defense nor prosecution wanting their BS testimony.
I’m not going to argue that families or friends can help in situations like you describe. But did you go public and tell the media what you found? That is my point. Keep quiet. Don’t blab evidence to the media.