Joshua Smith, 37, was also charged with attempted first-degree murder and obstruction.
Judge Raymond Myles, 66, was killed Monday outside his home and a 52-year-old woman he was with was wounded.
Chief of Detectives Melissa Staples said video from home surveillance systems played a key role in tracking down a car believed to be used in the attempted robbery. Cameras caught a license plate of the vehicle, she said.
Police said the couple was targeted.
"We do not believe (the attempted robbery) is random, nor do we believe Smith acted alone," Staples said, adding the shooting was not connected to Myles being a judge.
Smith was arrested after going to a police station to be questioned. He has a bail hearing on Thursday.
Staples would not say whether police think Smith, who has served six years in prison for armed robbery, was the gunman.
Misty Marris, a defense attorney not affiliated with the case, told HLN's "Primetime Justice" that you don't have to be the shooter to be charged with serious crimes.
"It's classic accomplice liability," Marris said. "If you're involved in the planning, commission or the getaway of a crime, you can be charged with that murder."
Case remains open
Ballistics evidence tied the gun in the Myles case to a robbery in January in which one person was shot.
"It underscores the very real problem of illegal guns that are used over and over to cause havoc in some of our communities," Staples said.
The investigation is "very open, active and ongoing," Staples said.
Police do not suspect the owner of the car was involved in the case, she said.
Myles was involved in the case against William Balfour
, who was convicted of killing singer and actress Jennifer Hudson's mother, brother and 7-year-old nephew.
The judge was also involved in the case of the 1993 massacre at a Brown's Chicken fast food restaurant in Palatine, Illinois, CNN affiliate WGN
Police said Tuesday the woman, whom they have not identified, was walking out of a home around 5 a.m. when she encountered the gunman.
"Upon hearing the commotion and the gunshot, Judge Myles exited his residence to investigate," Staples said. Myles and the shooter exchanged words, and the gunman shot Myles multiple times.
Staples said the two victims were known to regularly leave the home around 5 a.m.
"They would tend to go work out every morning together," Staples said.
CNN affiliate WLS
reported Wednesday the woman is in stable condition.