A mentally unstable man was convicted this week of taking part in the robbery of a female cab driver who was struck with the blunt end of a meat cleaver.

Antone Cortez Hall, 28, was found guilty but mentally ill on charges of robbery by force and battery during a bench trial held in front of Hall County Superior Court Judge Jason Deal. Deal sentenced Hall to 20 years, with 11 years to serve in confinement and the remainder on probation.

District Attorney Lee Darragh said a guilty but mentally ill verdict calls for a defendant to be evaluated for mental illness and treated accordingly, either in prison or a state hospital, but requires incarceration for the length of the sentence, regardless of the type of facility.

Hall was found guilty in connection with two separate cab driver robberies that occurred in November and December 2007.

A codefendant, 39-year-old Frankie Andrew Clark, pleaded guilty to a reduced charge of robbery prior to the trial and testified against Hall.

Clark is due to be sentenced next week.

Darragh said in both robberies, Clark called a cab to the ST&T Mobile Home Park off Browns Bridge Road. Both men got in the cab, with Clark riding up front next to the driver and Hall in the back seat.

After the cabs stopped, Hall would hold the cab drivers down from behind and Clark would strike them and demand money, Darragh said.

In the November 2007 robbery, the female victim was hit in the head with a shiny object later determined to be a meat cleaver, Darragh said.

She was able to fend off the robbers by shooting them with an electric stun gun.

Clark continued to fight with the woman and eventually wrested her wallet from her before fleeing, Darragh said.

A month later, the two men robbed a male cab driver under similar circumstances, Darragh said. The victim was held down and struck, but a weapon was not used. The driver’s wallet was taken and the men fled.

Hall County sheriff’s deputies arrested Hall and Clark shortly after the second robbery by tracking them down with a police dog.

The first victim later saw the men’s booking photographs in a newspaper and came forward to say they also robbed her, Darragh said.

Neither victim was seriously injured in the robberies.

Deal acquitted Hall of a charge of armed robbery, finding there was insufficient evidence to show that Hall knew a weapon was being used against the first victim.

Darragh said Hall has a history of mental illness, including schizophrenia, but has no prior convictions for violent crimes.