Family Member Murdered, But Cops On The Scene Ruled It As Suicide

This happened two days ago, a family member (Larry is what I'll call him for privacy) was discovered by his roommate with two sliced wrists, a sliced neck and stabbed chest. Along with that the room had plenty of objects broken and damaged, I can't get more specific than that. Cops responded to the scene and even after interviewing the neighbors (who reportedly, heard him screaming for help) deemed it a suicide. That morning, his roommate left him by himself, Larry was waiting on a weed delivery, and when he came back is when he was found. The cops kept his phone from what I know as evidence.

What's the next step here? There has to be something Larry's husband can do right? Or anybody else? It doesn't sit right with me whatsoever. They're throwing this shit on the backburner and wasting time. This is on my wife's side of the family and they're all distraught from it, and it disgusts me the police aren't even adding a detective to the case. I'm not entirely familiar with the ins and outs of law enforcement so please enlighten me on that or any advice to help them out. If nothing comes from this I'm considering contacting the local news and try to get some media attention on this.