The Man Who Knew Too Much

48 Hours Mystery Reports On Murder Of U.S. Journalist In Moscow

(CBS)  Musa says she doesn't know who is responsible for her husband's death: "I think Russia's very hard to understand. Paul was probably one of the people who really knew Russia the best."

But if taking on the powerful led to Klebnikov's death, then what really are the chances this murder ever will be solved?

Klebnikov's family not only misses the man they knew, they also mourn the man he was becoming. "All of a sudden you realize that this man is doing something which is pretty amazing, which is, in a small way, perhaps changing the world," says Peter Klebnikov.

And brother Michael vividly recalls a heart-to-heart talk he and Paul had the summer before the murder.

"It was a chrystal-clear day, beautiful white sand, cold water, nobody on the beach. And we just sort of lay side by side on our towels and caught the early June sun and talked about life, talked about Russia, about his ambitions, and his hopes."

Michael told his wife that for the first time he felt that his brother had "reached a level of impact and level of importance that I'll never be able to achieve. ... having an astounding impact on Russia and on the way that Russia's developing."

"Civil society requires a free press and killing the journalist doesn't solve your problems," adds Musa. "We need to solve this to make other journalists feel safe and I think the average Russian has to believe their country can be better. It's not just about killing people."

"There's a sense that this is sort of a litmus test for Russia," adds Peter. "Russia can never be a free democracy if they let these kind of people go loose."

Facing international pressure, authorities arrested one suspect late in 2004. And months later two others, all members of a Chechen gang. Russian prosecutors said the assassins were hired by this Chechen "Barbarian" featured in Klebnikov's critical book, a theory the family seriously doubts.

"We are working hard," says Glushchenko. "[This is] one of the most important cases for the general prosecutor's office."

But even if this case does have the full attention of the prosecutor, even if it is a top priority here at the Kremlin, contract killings still are notoriously difficult to solve.