As we all know, the media uses the term “unarmed” as a synonym for ‘harmless’. The sheer physicality of a 6’ 4”, 300lb ‘unarmed’ behemoth who is intent on inflicting physical injury is a weapon.
And who is likely amped up on drugs, compounding the danger.
The FBI reports that hundreds of people are murdered each year in the US by "Personal Weapons"; ie - fists, feet, hands, elbows, etc.
When you are attacked by a full-grown thug like Martin or Brown, they are definitely not "unarmed".
As an aside; if the FBI admits that the victims number in the "hundreds", then the real number is probably in the thousands.