This is clearly false. "He did it in the parking lot" is nothing like enough evidence to convict anyone. It isn't remotely enough even on the balance of probabilities. I have seen zero evidence for the conspiracy theory, and strong evidence against it, including the fact that his own family think his death was suicide.

Please do not casually spread conspiracy theories. They poison democratic debate, make us all stupider, and distract attention from important, evidenced realities, like the others mentioned in the article.