A jury at the Moscow City Court has found Yusup Temerkhanov, an ethnic Chechen, guilty of the murder of former Russian Army Colonel Yury Budanov.
Temerkhanov's lawyers say they will appeal the verdict.
In February, the court dismissed the previous jury, citing the "inability of some jurors to attend the process."
The defendant's lawyer insisted that the jury was dismissed to prevent it from acquitting his client.
Before the previous jury's dismissal, a witness in the case had changed his description of the killer, saying the defendant did not look like the man who shot Budanov in 2011.
Budanov was killed in Moscow two years after his early release from prison, where he served time for killing an 18-year-old Chechen woman, Elza Kungayeva.
Based on reporting by Interfax and ITAR-TASS