You are confusing the facts.
1) No one has been arrested nearly 3 weeks later since the raid. Where is the pay off?
2) The dead man has no criminal history and nothing illegal was found at his home according to the police. Where is the evidence of an illegal drug conspiracy tying the murdered man to anything?
There is zero there, no arrests, no case.
Great job.
The "evidence" was the fact that he had a brother who was known to the police. As others have noted, no effort was made to check out this particular guy on his own... they could have picked him up at work. Indeed, they could have figured out he was probably not a threat of violence, but they took the shortcut of assuming he was involved in the same activities as his brother.