A 24-year-old man has pleaded guilty to fatally shooting a man in the head at a Brooklyn Center gas station during a robbery in the midst of an illicit drug deal.

Giovanni V. Williams, of Minneapolis admitted Monday in Hennepin County District Court to second-degree murder in connection with the shooting in December of Dattreas Markeal Stewart, 45, of Brooklyn Center, at the Pump n’ Munch, 1505 N. 69th Av.

The agreement calls for Williams to be sentenced to a 20-year term. With credit for time in jail since his arrest, Williams will serve almost 13 years in prison followed by the balance on supervised release. A first-degree murder count will be dismissed during sentencing, scheduled for Oct. 19.

Prosecutors said police were called to the gas station about 9:15 p.m. and found Stewart in the front passenger seat of an SUV, where his girlfriend was holding a piece of clothing against his head wound. He died at the scene.

She explained to police that she had arranged with someone to sell an ounce of marijuana for $300, and that person put her in contact with Williams. The agreement was for the deal to be made at the gas station.

Williams got in the back seat of the SUV and told Stewart he was being robbed before shooting his victim once in the head, the charges read. Williams got back in his car with a bag of marijuana and left.