Updated story

At a vigil held at the site of the fatal shooting of 6-month-old Jonylah Watkins Tuesday night, the infant's family and their supporters gathered while the police investigation into her killing continues.

Among the 200 people assembled at the vigil was Judy Watkins, Jonylah's mother, who told DNAinfo Chicago she is looking for her daughter's killer and urging him to come forward.

"When I find him, he's going to jail," Judy Watkins, 19, told DNAinfo.

Police said Tuesday that they are still seeking a cooperating witness in the crime and do not have a lot to go on currently -- though, according to Fox Chicago, they have gotten surveillance video of what they think is the blue van the gunman used as a getaway vehicle.

Jonylah Watkins was rushed to Comer Children's Hospital Monday afternoon in serious-to-critical condition after being shot five times in the 6500 block of South Maryland Avenue in the city's Woodlawn neighborhood. Her father, Jonathan Watkins, had been changing her diaper in the front passenger seat of a minivan when a gunman approached them and opened fire.

Jonylah died around 6 a.m. Tuesday after doctors, nurses and medical technicians worked for 17 hours to try and save her. A Wednesday Chicago Tribune story details the lengthy work involved in the ultimately unsuccessful effort .

Jonathan Watkins, 28, was also wounded in the shooting and remains hospitalized at Northwestern Memorial Hospital in stable condition as of Tuesday , according to NBC Chicago. Jonylah's father has an extensive criminal record including 39 arrests, gang affiliations and was the intended target of the shooting, police claim.

When asked about that assertion Tuesday, Judy Watkins told DNAinfo she was not aware of the gang ties police were referencing. She also told the site that family members' reports that she was previously shot while pregnant with Jonylah -- who she described as "a happy baby" -- were untrue.

According to New Beginnings Church's Rev. Corey Brooks, who is acting as a spokesman for the family, Jonathan Watkins is cooperating with police on their investigation -- although he reportedly does not know who shot him and his daughter, the Chicago Sun-Times reported Wednesday.

Meanwhile, Jonylah's death has struck a chord citywide. It inspired a surge of submissions to the anti-violence "500 Project " social media campaign and prompted Bulls star Derrick Rose to offer to help pay for the baby's funeral, according to ABC.

The initial reward for information leading to an arrest in Jonylah's death has also been drastically increased to $15,000, thanks to contribution from the community, Fox reports.

Commenting on the child's murder in a Tuesday press conference, Mayor Rahm Emanuel described her death as "a senseless, despicable act of violence ," CBS Chicago reports.

Amid the investigation, Chicago's City Council on Wednesday considered a newly proposed registry that would treat violent gun offenders like sex offenders . The council voted to expand the gun offender registry , an action that will go into effect in the coming weeks.

No one is in custody in the shooting as of Wednesday evening and police are investigating. Anyone with any information or tips has been urged to call 1-800-883-5785, a number community activists have provided.