Aamer Madhani

USA TODAY

CHICAGO — Police charged a suspect Thursday in the killing of a Chicago-area judge, who was repeatedly shot in front of his home after he came to the aid of his girlfriend during an armed robbery.

Authorities charged Earl Wilson, 45, with first-degree murder for the April 10 fatal shooting of Cook County Associate Judge Raymond Myles. Investigators believe Wilson and another suspect were targeting the judge's girlfriend to rob, but officials declined to divulge why they believe the assailants had fixated on her.

"Based on our investigation of the offender and knowledge of the victim, that leads us to believe that this is not random," said Cmdr. Rodney Blisset, who heads the detective unit investigating the incident.

Wilson is scheduled to appear in court Friday for a bond hearing.

Police say Wilson approached the judge's girlfriend as she left the judge’s home on the city’s South Side before dawn. The assailants were aware that the woman and the judge left the home around the same time most days for an early-morning workout.

As the woman left the home, she was approached by the gunman and the two exchanged words. The suspect fired his weapon at the woman, wounding her in the leg.

Hearing the commotion, Myles ran out of the house and also exchanged words with the gunman, police said. The assailant fired several times at the veteran judge, wounding him in the right shoulder, left hip, twice in his left thigh and grazing his right-rear thigh.

Authorities said that the gunman snatched the judge's girlfriend's gym bag before running to a waiting getaway car. Myles' girlfriend survived the attack.

The alleged getaway driver, Joshua Smith, turned himself into police days after the incident and was charged with first-degree murder.

Prosecutors said at Smith's bond hearing earlier this month that while in the car the alleged gunman looked through the girlfriend's gym and became upset because there was no money inside it. Wilson had been following the judge's girlfriend for two to three weeks before the fatal shooting, according to prosecutors.

After the shooting, Smith told his ex-girlfriend and her daughter to lie to police if they were questioned, and tell them the car used in the crime — which belonged to Smith's ex-girlfriend — had been stolen and not been driven by him, according to prosecutors. Police say they do not believe the ex-girlfriend was aware Smith had intended to use her car in committing a crime.

Investigators were able to determine from bullet casings recovered at the scene that the weapon was also used in a January non-fatal shooting in Chicago. That shooting also involved a robbery, according to police.

Wilson was sentenced to 18 years in prison in 1992 after pleading guilty to attempted murder and home invasion for an incident in which he stabbed a former girlfriend. Police said he served 12 years for that incident before being released.

Wilson was taken into custody on Tuesday evening after officers apprehended him as he was leaving his home, but charges were not finalized until Thursday.

Myles joined the Cook County Circuit Court in 1999 when the Illinois Supreme Court appointed him to fill a vacancy. He had served in the criminal division for the last eight years prior to his killing.

Police told reporters Thursday that their investigation continues, but would not specify whether they are looking for additional suspects.

The incident is one of the more high-profile murders in the nation's third-largest city, which has seen a surge in gun violence over the last 16 months. Since the beginning of 2016, Chicago has tallied more than 900 murders and 5,000 shooting victims, more killings and shooting incidents than New York and Los Angeles combined.

Follow USA TODAY Chicago correspondent Aamer Madhani on Twitter: @AamerISmad