Employees at an Indiana grocery store helped lead terrified customers outside as a gunman prowled around the aisles Wednesday night, shooting and killing two people before he was taken out by police, authorities say.

Indiana State Police Sgt. Trent Smith said the gunman, Shawn Walter Bair, 22, was a regular at Martin's Super Market in Elkhart, and that there never have been any problems with him in the past. Smith credited Elkhart police and store employees for a quick response to the shooting, saying their actions saved lives.

At a news conference Thursday morning, Smith said Bair entered the store around 9:30 p.m. local time Wednesday and walked around for a half hour before leaving.

A security guard who knew Bair became suspicious as he watched the man because he wasn't buying anything.

"He took his time. I think he might have been hesitant while he was in the store. But whether he was watching people or picking out people, we'll never know," Smith said.

Bair then returned with a semi-automatic handgun and shot and killed a 20-year-old female employee, according to Smith.

Bair ran into another employee of the store and fired at her after having verbal exchanges, but she was able to escape, Smith said, citing video surveillance footage.

The second victim, a 44-year-old female customer, was shot multiple times about 12 aisles apart from where the first victim was gunned down, authorities said. The identities of the victims were not disclosed, pending notification of their relatives.

Smith said a store manager who was trying to figure out what was going on turned a corner and encountered Bair, who pointed his gun at the manager's face.

Smith said city police received a call about a gunman in the store shortly after 10 p.m. Officers who were nearby on an unrelated call arrived within three minutes and found the manager on his knees on the floor as if in prayer. Elkhart police shot and killed Bair and the store manager was able to escape after being held hostage for about 10 minutes, Smith said.

No motive for the shooting has been determined yet, but police say Bair might have had a relationship with one of the victims.

“The bravery and quick response of the Elkhart Police Department saved lives. No doubt,” Smith said.

Smith added that a couple of employees at the store also helped customers escape harm.

Police found a large caliber, semi-automatic handgun and a large knife near Bair, Fox 28 reports. Several rounds of ammunition were fired by the suspect and police officers during the incident, according to the report.

The Indiana State Police will investigate the shooting because the Elkhart Police Department was involved in the shooting, Smith said.

"We do have a lot of things to look at as far as video surveillance," Smith said, noting that state and city police also are interviewing witnesses.

A statement on Martin's Super Market’s Facebook page said: "Thank you to our community for your thoughts and prayers tonight. We will comment further when we can do so responsibly and appropriately."

Jessica Smith, the general manager at Fat Tomato, a restaurant next to Martin's, told WNDU.com that the shooting prompted a lockdown at her business.

"It was very scary," she told the station. "We had just finished up our night a little bit before 10 and we were put on lockdown by the police department. I was essentially holding 20-plus people hostage in my building."

"This is my neighborhood. This is where I live. I know so many people who work in there. This is devastating."

The Associated Press contributed to this report.