Police say Jason Austin killed Detective Robert Soto and Kathryn Romberg last Wednesday as they sat in Soto's SUV.
On Monday night, family, friends and fellow officers gathered in Summit to pay their respects to Officer Soto who was killed in an apparent robbery.
On the day of Officer Robert Soto's wake, Chicago police say there's a break in the case.
Monday morning Chicago Police announced Jason Austin was the shooter in the double murder and robbery of Officer Soto and Kathy Romberg.
Jason Austin is charged with two counts of murder and armed robbery.
Police say cameras nearby showed Austin's car before and after the murders.
"Video, it's a critical component of a lot of investigations. We do have what we feel is the offender's vehicle twice on private video in the area," said Chief of Detectives Thomas Byrne, Chicago Police Department.
At about 1:30 Wednesday morning, Officer Soto and Romberg were sitting in Soto's car in front of 3032 W. Franklin Blvd. when they were shot.
Chicago Police say that it was apparently a robbery that went bad. Authorities say that Officer Robert Soto's wallet was emptied.
Soto was able to call 911 immediately after the incident. Romberg, a Department of Children and Family Services supervisor who was also in the vehicle in 3900-block of West Franklin Boulevard, died at the scene. Officer Soto died on Thursday.
The suspect was in court Monday to hear a Cook County assistant state's attorney say witnesses told police Austin was the shooter and was seen leaving the scene.
"The defendant pointed a gun at the victims and the defendant demanded money. There were two occupants in the defendant's car who saw the defendant point the gun at the victims," said Maria McCarthy, Cook County Assistant State's Attorney.
But Austin's attorney says Austin has an alibi and is critical of the police investigating a murder of one of their own.
"We believe this was an opportunity for the police because of the intense personal nature of their investigation which they did in this matter, to use this as an opportunity to rustle up as many young men from the West Side of Chicago they could to charge in this matter," said Steven Decker, Austin's attorney.
Austin's aunt, also in court, says the car witnesses saw wasn't Austin's car. She says his car was in the shop until Thursday.
"Don't just go on hearsay...We've had enough of innocent people going to jail for things they haven't done," said Sharon White, Austin's aunt.
Jason Austin is being held without bail. According to police, Austin is a convicted felon and has served time in prison. His defense attorney points out that none of his convictions are for violent crime and that nothing in his history would point to similar criminal activity.