UPDATED 03/05/12 – 4:41 p.m.

MERILLVILLE, Ind. (CBS) – Police have released surveillance video and the 911 tape from an armed robbery that left a female store clerk dead in Merrillville, Ind.

As CBS 2’s Susanna Song reports, as of 11 a.m., there were still no arrests in connection with the Sunday afternoon robbery inside the Lucky Food Mart, at 5695 Cleveland St. in Merrillville.

LISTEN: WBBM Newsradio’s Bernie Tafoya reports

But police did obtain new surveillance video of the horrific robbery and shooting, which took the life of store clerk Judi Simpson-Beaver, 48.

An armed robbers hit the store around 1 p.m. Sunday. In the video, a robber is wearing a mask and a dark hoodie appears, jumping over the counter to steal the cash register.

Behind the counter, which is not visible in the video, Simpson-Beaver was working alone. The robber is seen raising a gun as he shoots her in the chest once, then comes back around to the front door.

But before leaving, police say, the robber went back to finish Simpson-Beaver off. Police said he shot her in the head.

The entire chain of events occurred within two minutes.

As CBS 2’s Dorothy Tucker reports, police also released the tape of a 911 call made by a woman who witnessed the shooting.

“We need an ambulance at Lucky Foods on Cleveland and 57th. Someone just robbed the store and the woman inside is bleeding,” the woman told 911 dispatchers.

When asked where the suspect was, she said, “We don’t know, he ran.”

Police said they think the shooting may have been more than just a robbery.

Merrillville Chief of Detectives Jim Lilley said Simpson-Beaver had complied with the robber’s demands, but he killed her anyway, shooting her twice.

Asked if police believe the gunman knew the clerk, Lilley said, “We’re checking all angles right now.”

“Maybe he did know her. That’s one of the angles we want to look at,” he added.

Police said Simpson-Beaver had moved to Indiana six months ago from Texas.

The Lake County Coroner’s office says the Simpson-Beaver died from multiple gunshot wounds.

The hoodie the robber was wearing was marked with text reading “Royal Estoc Empire” with a logo showing a knight’s helmet over three swords.

“Ultimately, he does obtain what appears to be some money from the store, and ultimately shoots the victim several times and then flees,” said Merrillville police Detective Joe Cooper.

Police say after the robber shot Simpson-Beaver, he headed to a getaway car that was parked nearby with possibly two other people inside. The gunman ran a short distance to get to the car, police said.

The car was described as an older model brown Oldsmobile with a discolored hood and a temporary Indiana license plate in the back window.

“Witnesses say there may be three involved. We’re now looking for an older-model brown Oldsmobile that was seen leaving the area right after the incident occurred,” Lilley said. “We’re asking any car dealerships that may have sold anything also please give us a call if they’ve sold any cars matching that description recently.”

CBS 2 also obtained additional video that shows two men walking outside the store, then into the store and finally leaving the store without making a purchase. That video was shot several minutes before the robbery occurred.

“They never made a purchase in the store,” Lilley said. “They walked up to the cashier … and then they walked out of the store. So, kind of suspicious to us.”

Concerned citizens were distributing flyers outside the store Monday, asking the public to help find the gunman.

“It’s senseless, and these animals who killed her, you know, they must be brought to justice,” Dwight Taylor said.