A Marietta man convicted of robbing an ATM customer after his DNA was found on cigarettes at the crime scene was sentenced Monday to 40 years in prison.

On Friday, a Cobb County Superior Court jury convicted Derrius Shamar McKinney for the Sept. 13, 2012 armed robbery and aggravated assault of a 59-year-old man who had just used the ATM at the Bank of America branch in the 2400 block of South Cobb Drive.

The victim was hit in the head with a gun and robbed of $160, according to Kim Isaza, spokewoman for the Cobb district attorney's office.

Isaza said DNA found on cigarettes near where the victim said the perpetrator's car was parked matched that of McKinney.

Cobb Superior Court Judge Mary Staley Monday morning sentenced McKinney, 23, to the state's recommendation of 40 years.

Co-defendant Shawn Thomas pleaded guilty in the case and was sentenced to 15 years, with 10 years to serve, Isaza said.