I'm very sorry for your loss. I think the best thing you can do at this point is try to find some evidence that your brother's death involved some sort of foul play. Was an autopsy done? If so, the coroner likely detailed everything found in his system, like any potential drugs, alcohol or food, and any injuries, like bruises or broken bones. Once you have a more accurate picture, I would take the information to the lead investigator on the matter. Explain exactly what you found, based on physical/proven evidence. With that information, there is no way they can brush the case to the side. Good luck.
