WHY would Cuban security agents choose to kill the island's leading dissident while he was in the company of two Europeans who might bear witness to the crime?
To outside observers, it's an intriguing mystery. For those directly affected, even to ask the question is, in some sense, to surrender to the malign influence of authoritarian control.
That was one message this week from two inspiring young women, daughters of courageous democracy activists from opposite sides of the world, who happened to be in Washington at the same time.
"I'm not so anxious to understand the perverse logic of repression," Rosa Maria Paya, 24, replied when I asked why agents might have targeted her father that way.
"I don't think there is a reason to kill anyone," she added. "And I shouldn't have to be having to answer that. This is a question to put to the people who threatened his life on a daily basis."
Violence, censorship and imprisonment are the obvious weapons of dictators, from Cuba to China. But the tools of repression also include caprice. If no one can be sure who will be targeted and who will not - when rule by whim replaces rule of law - then everyone must live in fear.
That is the dictator's hope. Paya and Ti-Anna Wang, 23, decline to play along.
Wang's father, Wang Bingzhang, is a democracy activist who was living in exile in North America 11 years ago when he traveled to Vietnam for a meeting with Chinese labor activists.
He was kidnapped, bundled across the Chinese border, held incommunicado for six months and then, after a closed one-day trial, sentenced to life in prison on spurious charges of terrorism.
Why was Wang targeted and not other exile leaders?
For that matter, why has his daughter not been granted a visa to visit her father for the past four years? Each application has been denied - without explanation. Ti-Anna Wang said she refuses to waste time speculating on motivation.
"The arbitrariness is designed to break your spirit," she said. "We really can't dwell on wondering why they do what they do, or fear what they might do, because those thoughts are crippling."
Paya's father, Oswaldo Paya, was the leader of a peaceful movement advocating free elections and human rights in Cuba. He died last July in what the Cuban government has called a one-car accident, in which the driver, a Spanish sympathizer of Paya, supposedly drove into a tree.