"How could this be justified? They took my sister away from me," said Martinez Sutton, the brother of 22-year-old Rekia Boyd.
The suburban man is grieving the loss of his sister, who died Thursday at Mount Sinai Hospital after being shot in the head by an off-duty Chicago police officer.
Boyd and a man were both shot early Wednesday morning by an off-duty detective on the city's West Side.
Family and friends who were at Boyd's side when she passed away Thursday are calling for a federal investigation into her death.
Boyd's family insists she was an innocent bystander.
"This young beautiful girl dead in the streets. Why?" said Sutton.
Boyd's family brought two photos of her Thursday to the hospital. In the first, she is a smiling, happy 22-year-old woman. The second photo was snapped shortly before she died.
"All we want to know is what happened?" said Sutton.
Just after 1 a.m. Wednesday morning, the police union says, an off-duty detective rolled down his car window and asked a group of people gathered near Douglas Park to quiet down. In response, police say, a 39-year-old man pointed a gun at the officer, who drew his own weapon and fired. The bullets hit the alleged gunman in the hand and Rekia Boyd in the head as she stood nearby.
"They said the shooting is justified, but how is it justified when you got a young girl up there with a bullet hole in her head? What kind of justice is that?" said Sutton.
Witnesses told ABC 7 Wednesday that no one pulled a gun on the off-duty officer. And prosecutors only charged the man who police say had a gun with aggravated assault, a misdemeanor.
"There were 60-70 people in the park and no one had a gun. Everyone was just out there to hang out, that's it," said witness Leo Coleman on Wednesday. Coleman is the alleged gunman's cousin.
Boyd's large family from south suburban Dolton sees similarities between what happened to her and the case of the unarmed Florida teen shot by a neighborhood watch volunteer.
"First you got Trayvon, now you got Rekia," Sutton said. "Senseless, senseless violence. It didn't have to happen."
The Independent Police Review Authority is investigating the shooting.
Late Thursday afternoon, the Chicago Police Department told ABC 7 that CPD had been in contact with Boyd's family and would like to express sincere condolences.