I genuinely don't understand why you keep making disparaging assumptions about Joshua Brown, a victim just murdered.
1. Joshua voluntarily cooperated with LE investigating Jean's murder. He didn't have to, and many peeps wouldn't have. I'd wager that close to none would in his position, given his fear of being hunted down by the guy who had shot him.
Not wanting to testify at all, much less for the State ("snitch!!!!!") in a high profile murder trial is RATIONAL, not evidence of a "sketchy" past.
2. You mock the description of him as a "good boy." Boy? He was a 28 year old man. With a college education, employed, and willing to voluntarily provide evidence to LE to help get justice for a man he met for the first time the day he was murdered. The only mark against him, for those looking to impugn his character, is that he been busted once on a drug charge. Big whoopity.
3. Maybe he knew suspect #2, maybe he didn't. What difference does that make? Guilt by association?
((Suspect #2 was never arrested. If Joshua knew him, Joshua chose not to turn him in. Why would suspect #2 come after him now?))
4. The background of trial witnesses doesn't "get buried." Joshua was a State witness. The defense team was allowed to depose him, ask him whatever they wanted, and to have used it against him at trial to discredit his testimony. If there had been anything relevant or useful. Nope.
Joshua was an effective witness. He is also a victim.