Frank Spano worked his way down a line of guests, welcoming the men in fedoras and women in flapper dresses to his hidden nightclub. He was tall, wore a grey suit and spoke with old-fashioned politeness. When he shook my hand and introduced himself, I shared a knowing smile with the other guests. We were all aware that Frank Spano would soon be shot dead in the narrow alleyway where we stood. We were here to find out why.