Inexcusable and absolutely shameful.
CHICAGO, Illinois (CNN) -- A gunman who shot and killed five women in a clothing store at a suburban Chicago strip mall Saturday remains at large, police said.
Police investigate the scene of a shooting at the Brookside shopping center in Tinley Park, Illinois.
The motive for the shooting at the Lane Bryant store was a robbery that "at some point went rather poorly," said Tinley Park police Sgt. T.J. Grady.
All of the victims -- ranging in age from 22 to 37 -- were found in a back room of the store, he said. Their identities were not released.
"This is a very serious and sensitive investigation," Tinley Park Police Chief Michael O'Connell said Saturday evening.
At least one of the victims was a Lane Bryant employee, O'Connell said. The store did not have a security camera, he added.
A 911 call reporting the shooting came in at 10:44 a.m., Grady told reporters.
The shopping center was locked down while stores were thoroughly searched. It was reopened after police determined the gunman had left the area. Watch police describe the crime scene »
Shoppers described a tense situation after the shooting.
"I was so scared I couldn't think," said Selena Kujawa, who was in a Target store across from the Lane Bryant store, according to The Associated Press.
She and other customers watched as police checked aisles with weapons drawn, the AP reported. There was a similar scene in a pet supply store nearby.
"Six police entered the store with their hands on their gun holsters," Tracy Caccavella told the AP.
The gunman was described as an African-American man, about 5 feet 9 inches tall and weighing between 230 and 260 pounds, Grady said. He was wearing a waist-length black winter coat, a black cap and dark jeans.
Authorities believe there was only one shooter, Grady said. Helicopters helped in the search for the gunman, who is no longer believed to be in the immediate area, he said.
Authorities were downloading surveillance video from businesses within a mile and a half of the Lane Bryant store to see if any cameras captured the gunman.
Police appealed to the public for help, urging anyone with information to contact police at 708-444-5368.
The Chicago Tribune reported the shopping center is just south of Interstate 80 and contains a Super Target, a Kohl's clothing store and several restaurants.