The third person charged in the 2009 murder of the owner of a Northeast Washington pizza shop was sentenced to 20 years in prison Thursday by a D.C. Superior Court judge.

Isiah Genus, 28, pleaded guilty to second-degree murder after he was arrested in connection with the Aug. 18, 2009 beating and stabbing death of Shahabuddin Rana, 44, the owner of the Pizza Mart in the 2300 block of Fourth St. NE. He was sentenced by Judge Frederick Weisberg.

Also charged in the murder were Shanika Robinson, 29, Genus’s girlfriend at the time, and her brother Leon. Last week, Judge William M. Jackson sentenced Shanika Robinson to 54 years in prison after she was convicted of second-degree murder and orchestrating the killing.

Jackson sentenced Shanika’s brother, Leon, 27, who was convicted of first-degree, premeditated murder, to nearly 76 years in prison.

Genus cooperated with prosecutors and was a key witness in the Robinsons’ trial this summer. Genus testified how he cut Rana’s throat during the attack, but that it was Shanika Robinson’s plan to kill her brother-in-law after Rana stopped paying her the $500 a week he promised in exchange for her marrying his younger brother, a Pakistani national.

Fueled by revenge and anger, prosecutors said, Robinson sought the help of Genus and her brother in hopes of frightening Rana into continuing the payments. Prosecutors said the men would not have been involved in the murder but for their desire to seek favor with Robinson.

About 4 a.m. Aug. 18, 2009, prosecutors said, the three drove to the Pizza Mart in the 2300 block of Fourth Street NE, where Rana worked the overnight shift. Robinson persuaded Rana to let her in through the front door while the two men hid. As Rana opened the door, the men pushed their way inside.

Genus repeatedly stabbed Rana as Leon Robinson wielded a hammer, prosecutors said. While the men were attacking Rana, Shanika Robinson was in another part of the store grabbing about $2,000 in cash and cigarettes. Before the three fled, they tried to set Rana’s body on fire, prosecutors said.

Following Thursday’s sentencing, Leon Robinson’s attorney Kevin McCants was disappointed by what he perceived as a leniemt sentence for Genus. McCants said the government gave Genus “too much credit” for pleading guilty.

“He got a third of the crime but did most of the damage,” McCants said.