Steven Johnson, 25, and his mother were arrested Thursday after a police raid on their home in Washington Park.
Prosecutors contended Jackson shot Thornton several times in the chest as the 52-year-old sat in his car on April 1, 2010.
Steven E. Johnson is charged with several crimes including promotion of prostitution, but not for holding alleged victim against her will.
Quinn signed a bill Thursdaythat creates the Metro East Police District Commission with public officials and police from East St. Louis, Alorton, Brooklyn and Washington Park.
It broke out along Route 111 near I-64 after a train went through
FBI, ATF agents to track down violent criminals and gangs
More than 10 shootings, two murders, in eight-month long battle
Aaron Jackson faces life in prison
Prosecutors contend Aaron Jackson shot John Thornton three times in the chest as the 52-year-old mayor sat in his car.
The car’s driver and train operator rushed to the hospital, but passengers on train escape injury.