Gunman on the loose after 5-month-old girl killed sitting in car in Chicago

A 5-month-old baby was killed while sitting in a car in Chicago during a violent weekend in which at least 20 people were shot in the city, according to police.

The infant girl was by far the youngest of four people fatally shot in separate incidents in Chicago since Friday, police said.

Homicide detectives were working on Sunday to identify a suspect or suspects in the baby's death.

The baby was identified as Cecilia Thomas by the Cook County Medical Examiner's Office, which determined she died from a gunshot wound to the head.

The deadly shooting occurred Friday evening in Chicago's South Shore neighborhood, according to the Chicago Police Department.

The girl was being driven home by her father when shots rang out at about 6:45 p.m., police said. The father immediately pulled over and summoned help, police said.

The child was taken to Comer Children's Hospital, where she was pronounced dead.

A 41-year-old motorist driving by when the shooting occurred was also hit by gunfire, police said. The wounded man drove himself to the University of Chicago Medical Center, where he was treated for a gunshot wound near his eye, police said.

No arrests have been made in the homicide and a motive is under investigation, police said.

Andrew Holmes, a victim advocate and crisis responder in Chicago, told reporters that he spoke with the baby's mother, who said her daughter was being driven home when she was shot.

"That's a five-month-old baby. Nine months she carried that baby, nourished that baby. And it takes a damn fool to discharge that weapon and take a baby's life," Holmes said.

The shooting occurred during another violent weekend in Chicago, where at least 20 people were shot, four fatally, in a string of separate incidents, according to police.

The shootings followed last weekend's gun violence in Chicago that left a total of 61 people were shot, 10 fatally.

Investigators were combing through video from surveillance cameras in the area in hopes of finding footage of the episode that could help them identify those responsible, officials said.

"I hope you don't have no children yourself. Because if you do, you shouldn't sleep at night," Holmes said.

Among the other fatal shootings this weekend, a 32-year-old man was mortally wounded after getting out of his car in Chicago's city's Little Italy, according to police. The victim was shot twice in the chest and was taken to Stroger Hospital, where he was pronounced dead. No arrests were announced.

Two other men were killed in separate shootings Friday night that were three miles apart, according to Chicago police.

A 21-year-old man died after being shot multiple times in the Princeton Park neighborhood on the city's South Side, according to police. An hour earlier, police discovered a 45-year-old man shot multiple times in the nearby Pullman neighborhood and later died at a hospital. Investigators were working Sunday to identify a suspect or suspects in the homicides.