What’s your definition of robbery?
Stealing a gun from a vehicle. That’s a close definition of a robbery. A burglary if you will.
The younger McMichael claims that a weapon was stolen from his truck recently. Did this actually happened? Who knows and if it did was Arbery the one who took it? Again, who knows. But if the McMichaels had reason to suspect that Arbery was in fact casing the joint last October. If they had reason to suspect he stole the gun from their truck. If they had reason to suspect that he was once again up to no good in their neighborhood; then yeah. They have every reason, every right to chase him down.