Civil rights leader Jesse Jackson and relatives of victims of fatal shootings in Chicago urged President Barack Obama on Saturday to come back to his hometown and address the gun violence plaguing the city. Before a march on the city's South Side, Jackson, a former Democratic presidential candidate, said America's third most populous city needed more help than Mayor Rahm Emanuel and police superintendent Garry McCarthy could offer. Gun violence in Chicago has been in the national spotlight over the past year, with 506 murders in 2012, an increase of 17 percent from the previous year. As of Thursday, there were 42 homicides and 157 shootings so far this year, according to Chicago police.