Published: Mar 12, 2013 3:55 PM EDT

CHICAGO (AP) - An attack in which a 6-month-old girl was fatally shot and her father was wounded was apparently gang-related, and authorities said Tuesday that they are searching for the gunman and the driver of the getaway van.
    
Jonylah Watkins was shot five times during the Monday afternoon attack in the South Side neighborhood of Woodlawn. She died Tuesday morning at Comer Children's Hospital, police said.
    
Her father, Jonathan Watkins, was in serious but stable condition, recovering at Northwestern Memorial Hospital from wounds to his side, buttocks and face, which was only grazed, police said.
    
Witnesses said the attacker approached Jonathan Watkins around 1 p.m. while he was standing beside his minivan and changing his daughter's diaper. She was on the front seat. Her family said Jonylah was shot in the thigh, shoulder, lung, liver and bowels.
    
Jonathan Watkins belongs to a gang and has a long criminal history, and Monday's attack appears to have been gang-related, Police Superintendent Garry McCarthy said at a Tuesday news conference. He said police weren't sure yet whether Watkins will decide to cooperate in the investigation.
    
"No child, certainly not an infant, should be a victim of gang violence," McCarthy said.
    
Authorities found surveillance video of the blue van in which they believe the attacker fled. They believe a driver waited in the van during the shooting.
    
McCarthy said police flooded the neighborhood Monday night to prevent a retaliatory attack over the infant girl's shooting.
    
"He was obviously targeted," McCarthy said of Jonathan Watkins. Police were trying to determine whether a reported Facebook post threatening Watkins actually exists, McCarthy said.
    
It wasn't the family's first brush with Chicago's gun violence. The girl's mother, Judy Watkins, was shot in the knee while she was pregnant with Jonylah, according to the woman's mother, Mary Young.
    
"There's too much shooting over there," Young told reporters Monday. Speaking of her granddaughter, she added, "She's nothing but 6 months old. How could anybody - what kind of heart?"
    
Chicago has seen a rise in gun violence - much of it gang-related - and registered at least 500 homicides last year for the first time since 2008. In 2011, there were 435 homicides.
    
McCarthy had told reporters Monday that homicides were down 26 percent this year, compared with the same period a year earlier. On Tuesday, he said: "It's hard to see the progress."

(Copyright 2013 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)