The Prosecutor General's Office charged Pichugin in July 2005 with organizing two murders and two attempted murders.
Speaking in court, Pichugin asked the court to fully examine the case and to pass a just sentence. He also said he did not know any of the other accused people in the dock.
Defense lawyer Georgy Kaganer said Pichugin had had no motive for committing the crimes he was charged with.
The prosecution pressed Tuesday for a life sentence for the defendant.
Alexei Pichugin, who is already serving a 20-year sentence for two killings and an attempted murder, pleaded not guilty on May 16 to new charges of murder and attempted murder dating back to 1998.
The other defendants in the case have admitted their guilt on some of the charges: the attempted murder of businessman Andrei Rybin, and the murder of entrepreneur Valentina Korneyeva.
Prosecutor Kamil Kashayev said, "The guilt of the defendants has been fully proved by the evidence of witnesses and case materials."
The prosecutor demanded sentences from nine to 12 years in prison for other defendants.
The Prosecutor General's Office brought the new charges against Pichugin last July. He is accused of murdering Korneyeva, the head of the administration in the Siberian oil town of Neftyugansk, and the attempted murder of Rybin.
