UPDATED 03/07/12 – 6:37 p.m.

MERRILLVILLE, Ind. (CBS) — Authorities have charged a 20-year-old Merrillville, Ind., man with the convenience store robbery and shooting that left a clerk dead over the weekend.

But they are still looking for two other suspects.

Jeremy Blue is charged with murder, murder in the perpetration of a robbery, and robbery, police said. He is accused of killing Judi Simpson-Beaver, 48, after he robbed the Lucky Food Mart, at 5965 Cleveland St. in Merrillville, on Sunday.

As CBS 2’s Dana Kozlov reports, police said Blue was identified by eyewitnesses who saw the gunman walk out of the convenience store after the robbery.

A robber stormed into the store on Sunday afternoon. In a surveillance video, he is seen wearing a mask and a dark hoodie, jumping over the counter to steal the cash register.

Judi Simpson-Beaver was shot and killed during a robbery at the convenience store where she worked in Merrillville, Ind., on March 4, 2012. (Family Photo)

Behind the counter, clerk Judi Simpson-Beaver was working alone. Police said she complied with Blue’s demands, but he shot and killed her anyway.

“This was a heinous crime. I mean, she did everything she was supposed to do. She complied,” Merrillville Chief of Detectives Jim Lilley said. “This was pretty much ruthless for him to do what he did.”

Detectives said dozens of anonymous tips, including one from a witness who saw the gunman fleeing the scene, helped police find Blue.

Simpson-Beaver’s family was thankful there was such a quick arrest in the case.

“When he was fleeing, he had lifted the face mask up and the witness had gotten a clear shot of his face,” Merrillville Police Chief Joe Petruch said.

A SWAT team surrounded Blue’s Merrillville home Tuesday until he surrendered, but Blue’s sister – who did not want her name used – said Blue didn’t do it.

“He was at home all day. … All day; he don’t do nothing, but sleep.”

But Simpson-Beaver’s son Zach Beaver, said he was confident police arrested the right man.

“I have complete faith in the local law enforcement,” he said. He and his two uncles said they hope police also catch the two men who went into the store before the robbery, and who police believe were Blue’s accomplices.

Two other men were seen with Blue in the getaway car.

“They not only hurt the community, our family, this area; they’ve also hurt their family,” Simpson-Beaver’s brother, Dee Simpson, said.

Detectives said they still haven’t recovered the gun, the mask, or the jacket used in the robbery. But they said they do have the getaway car used in the crime. The car belonged to Blue and investigators have been processing it for evidence.

Police also said they are questioning several other people in connection to the robbery.