You can locate many articles challenging the official story of the RFK assassination by doing a bit of research on the internet.
Evidence found on the scene included photos taken by student Scott Enyart, which were seized then destroyed many years later when he asked for them to be returned.
Door jambs which reportedly had bullet holes in them were also destroyed by the LAPD.
I'm aware of this but I'm not that interested to spend the time looking into it. That's why I asked those more knowledgeable than myself about this topic: is there any physical evidence to suggest more than one gun was used? Missing items make for great conspiracy pieces but too often have legitimate, non-conspiratorial reasons.
Otherwise, I'm very skeptical of witness testimony about something as specific as the exact number of gunshots heard when multiple shots were fired in a chaotic situation.