The family of the victim, Jose Nieves, spoke after Thursday's court hearing.
Officer Lowell Houser, 57, stood in court in street clothes, just the second Chicago police officer charged with first degree murder in more than three decades.
The prosecutors asked the judge to deny bail but the judge set bail at $150,000. Houser has to post 10 percent, or $15,000, to be released.
Family members of the victim were in court as prosecutors described the shooting.
"Does it bring justice? Does it bring a little bit of closure to us as a family? It just brings us knowing that my brother's voice is being heard," Angelica Nieves, the victim's sister, said.
Prosecutors said the shooting stemmed from an argument on the morning of January second on the street in front of Houser's girlfriend's home.
"Defendant was standing in the parkway near the driver side of his own vehicle pointing a pistol toward Nieves. Individual B then heard two more bangs. Individual B then saw nearest place his hand on his chest and fall backwards to the ground," Lynn McCarthy, assistant State's Attorney, said.
Houser is a 28-year veteran of the department. His attorney said he has been on medical leave since last spring because he has prostate cancer and he was planning to retire at the end of the year.
His attorney claimed in court he fired in self-defense and said that Nieves, "made an action as if he was reaching for a weapon."
Investigators found no weapons on the scene other than the officer's revolver. The family has also filed civil suit against the Houser.
"This officer was operating within his police powers, with his badge, with his gun and unjustified and unreasonably used excessive force," Andrew Stroth, the family's attorney said.
"I will not stop and I will fight for justice for my brother," Angelica Nieves said.
ABC 7 was told he is still in prison as of 4:30 p.m.
Houser, was arrested and charged Wednesday for the murder of Nieves after a swift 16-day criminal investigation of the incident, according to the Cook County state's attorney.
The State's Attorney's Office said the charges came straight from Kim Foxx's office, and that the FBI, Chicago Police Department and IPRA had nothing to do with the decision.
Police said Nieves was unarmed when he was fatally shot by an off-duty police officer on Jan. 2 in the 2500-block of North Lowell Avenue in the Hermosa neighborhood after an argument with the officer escalated.
"The person who was shot did not have a weapon. That much we know. The officer's weapon is the only one we found," police spokesman Anthony Guglielmi said.
Houser was stripped of his police powers the day after the shooting.
A memorial stills sits on the sidewalk outside Nieves' Hermosa apartment where he died. Family said they had once been neighbors and had clashed before.
I-TEAM: WHO IS LOWELL HOUSER?
The I-Team looked into Houser's background, who he is and what his record is with the police department.
Houser is currently assigned to the mass transit unit, and has been the subject of numerous police disciplinary investigations over the years but none involving shootings, the background check revealed.
There is no mention in the complaint or arrest warrant that Houser is a police officer, although his address is listed as 3510 S. Michigan Ave. - CPD headquarters. The state's attorney has requested he be held without bail.
Years prior the shooting, Lowell had deep financial problems. There were multiple liens against him from banks and credit unions, totaling tens of thousands of dollars. He filed for federal bankruptcy in 2004.
Howell has been the subject of multiple complaints filed against him, according to the Citizens Police Data Project; reportedly more than 20 complaints over the past two decades. Several resulted in suspension, and one is said to have involved an off-duty disturbance in 1994.
Houser is now the second Chicago police officer facing murder charges. He joins former officer Jason Van Dyke, who was charged in the shooting death of Laquan McDonald. McDonald's shooting prompted the review of CPD practices and sharply critical report from the Justice Department.
Click here to read the arrest warrant and preliminary complaint.