Mustafa Mahmud was referred to an expedited trial after he shot dead Mohamed Ali Sayed Ismail with his police issue firearm in February, sparking rare protests and an apology from the interior ministry.
Mahmud had hired Ismail to transport his belongings when they had a dispute over the fare that turned violent.
A life sentence in Egypt is 25 years. Mahmud can appeal the verdict issued by the Cairo criminal court.
Police have been on the defensive after a string of deaths in custody, reminiscent of abuses that sparked an 18-day uprising that toppled longtime president Hosni Mubarak in 2011.
Five years on, human rights groups are again denouncing torture and deaths in police stations, arbitrary arrests and the disappearances of opponents of the regime.
In February, thousands of doctors held a protest against the police after officers allegedly assaulted two doctors in a hospital.
Over the past year, several policeman have been detained for violence against prisoners and some have been sentenced to jail.
