CHICAGO (WLS) -- A 28-year-old woman who was seven months pregnant was one of [url HREF="[br /]http://abc7chicago.com/4-killed-in-brighton-park-shooting/2421980/" TARGET="" REL=""]four people fatally shot Friday night in Chicago's Brighton Park neighborhood[/url], her father and step-mother confirmed.[br /][Ads /][br /]Ida Arvizu, along with three men, were in a vehicle in the 4700-block of South Fairfield Avenue around 8:30 p.m. when they were shot, police said.[br /][br /]Arvizu, who worked as a dental hygienist, also had a 7-year-old daughter, her family said.[br /][br /]The other victims were identified to the Cook County Medical Examiner's Office as 21-year-old Michelle Cano, 24-year-old Joel Sandoval and 27-year-old Miguel Sandoval.[br /][br /]Sandoval was Arvizu's ex-boyfriend and the father of both of her children. The baby already had a name - Reymundo.[br /][br /][media ID="2423434" /][br /][br /]The two other victims were friends that he'd picked up to run an errand. The victims have relatives who lived in the area where the shooting occurred.[br /][br /]Step-mother Ana Arvizu said Ida Arvizu was reluctant Friday night to meet up with Joel Sandoval, who she recently broke up with.[br /][br /]Circumstances surrounding the shooting remained unclear Saturday, but investigators said the shooting appeared to be gang related.[br /][Ads /][br /]No one was in custody Saturday in connection with the shooting.[br /][br /]Ald. Ray Lopez (15th Ward) said the shooter used an assault rifle.[br /][br /]"Weapons of war are winding up on the streets used by gang members to fuel their Facebook blood sport to see who can try to outdo who," Lopez said.[br /][br /]Witnesses described hearing heavy gunfire.[br /][br /]"Just heard the machine gun, probably 12 rounds go off and the first thing I did was duck down and hover over my mom and tell her to duck down because she was freaking out. Just as soon as I heard the last shot, I took off and called the cops," said one witness.