Columbia - The man convicted of killing nine worshippers during Bible study at a black church in Charleston, drove toward a second black church after the shootings, according to South Carolina prosecutors who oversaw the federal case against him.In court documents unsealed on Tuesday, federal prosecutors said they had GPS evidence showing that Dylann Roof exited the interstate and drove toward a church in Summerville, about 50km from Charleston's Emanuel AME Church, after committing the June 2015 slayings. According to the government, Branch AME Church also had a sign that advertised a Wednesday night Bible study.Prosecutors said Roof, now 22, shut off his GPS device, something they say indicates he stopped the car.None of these specific details were part of the case against Roof, who was sentenced to death last month. In December, a jury convicted him of 33 federal charges for killing nine people as they prayed at the end of a Bible study at the historic Charleston church known as Mother Emanuel.During trial, prosecutors presented evidence showing Roof had lists of other black churches in his car when he was arrested in Shelby, North Carolina. During a lengthy confession the day after the shootings, Roof told FBI agents he was too tired after the Emanuel killings to carry out any other violence.State prosecutors are pursuing the death penalty against Roof for murder charges, but that trial was indefinitely postponed during his federal proceedings. Roof is also seeking a new federal trial, saying prosecutors didn't have jurisdiction to bring their case against him.