Witnesses say a man walked up to her, opened fire and then escaped in a waiting car.
Medina's family later learned she was four months' pregnant.
Police are still searching for the gunman.
Vigil held for pregnant woman shot to death
CHICAGO People exchanged words of comfort in the 4100-block of W. 24th St.
That's where Nicole Medina, 20, was shot and killed Saturday in front of her aunt's home.
