Mercenary

He was walking barefoot on the street taking photographs of a truck - visible tattoo on his foot.  A white African - born in Zimbabwe; his father was a mercenary (Executive Outcomes) and was decapitated in Sierra Leone; his mother raped and killed too.  He was nine at the time.  Moved to South Africa and eventually became a mercenary too.  Three tours of duty in the Middle East including two in Iraq with the now infamous Blackwater organization.  The tattoo on his foot said I'd Rather Die on My Feet.

I'm sure the stranger who agreed to engage with him had a story too but I didn't get it.

Alternates including a couple of guys trading beer for eggs.