Shot In The Back Oct 10, 1980

First, there was a visit by a famous writer to his old friend, who then, in order to get rid of a random witness, killed him. Envy and money. Isn't that a motive for a crime? The police opened a criminal case, and the search for the perpetrator began. It turned out that there were many witnesses. But the weapon used to kill the writer has not yet been found...