Authorities said Monday that a 20-year-old man constructed a rifle in a suburban Indianapolis shopping mall toilet before opening fire on five people in the food court, killing three before an armed shopper fatally shot him.

Jonathan Sapirman of Greenwood was probably facing eviction when he opened fire at the Greenwood Park Mall just before it closed on Sunday evening, according to James Ison, the city's police chief.

Sapirman proceeded to shoot victims until he was killed by 22-year-old Elisjsha Dicken of Seymour, a city around 72 kilometers (45 miles) south of Greenwood, who was shopping with his fiancée, according to Ison, who described Dicken's prompt action as "nothing short of heroic."

"Many more people would have died last night if a responsible armed citizen had not intervened," said the chief, adding that officials were still investigating the attack's purpose.

The Johnson County and Marion County coroners' offices identified the deceased as Pedro Pineda, 56, and Rosa Mirian Rivera de Pineda, 37, both of Indianapolis, and Victor Gomez, 30, both of Indianapolis. According to authorities, the attack injured a woman and a 12-year-old girl with shrapnel.

Although investigators stated that Dicken was legally permitted to carry a firearm, the mall prohibits guns on its premises. The mall released a statement expressing sorrow for the victims and praising Dicken's "brave actions." It did not disclose its no-weapons policy, and its operator, the Simon Property Group, declined to comment.

As of July 1, Indiana law permits anyone 18 or older to carry a firearm in public, except those barred for a felony conviction, a restraining order, or a court-determined mental severe disease. The Indiana legislature, dominated by Republicans, maintained measures that allow private property owners to outlaw weapons.

The assault Sunday was the latest in a string of mass shootings in the United States. Schools, churches, grocery stores, and a Fourth of July parade near Chicago have become killing grounds in recent months. However, the country's staggering murder rate is often more evident in individual killings that rarely make the news.

On Sunday, authorities stated that four victims were female and one was male. On Monday, however, they revised their statement to two males and three girls.

Ison stated that Sapirman entered the mall and a restroom, where he remained for almost one hour before opening fire. According to this source, investigators suspect that Sapirman spent that time prepping and maybe reassembling a dismantled gun he had in his rucksack. He ultimately fired 24 bullets in two minutes.

Ison stated that Sapirman used a rifle resembling an AR-15 during the shooting and that detectives discovered a second one in the restroom. They also found a handgun on Sapirman, wearing a waistline holster and carrying more than 100 rounds of ammunition in multiple magazines.

Sapirman's relatives told investigators that he had just received notification that he was being evicted from his flat, but Ison stated that officials are still attempting to confirm this. Relatives also told him that he claimed that Sapirman quit his warehouse job in May.

"Currently, we have no purpose. The members of his family with whom we spoke were as astonished as everyone else. "They reported that there were no indications that he was violent or unstable," Ison explained.

As Dicken fired ten bullets from his revolver, Sapirman "attempted to retreat into the restroom but failed and fell to the ground after being shot," according to the chief.

"He engaged the assailant from a considerable distance with a handgun and was quite proficient and tactically smart in that regard. "As he moved closer to the suspect, he also motioned for those behind him to exit," Ison said of Dicken.

The chief stated that Sapirman had a juvenile record, including a brawl at school and an occasion in which he ran away from home, but no adult criminal record.

He stated that relatives of Sapirman informed investigators that he had been practicing shooting at a gun range and that documents collected by the Bureau of Alcohol, Tobacco, Firearms, and Explosives indicated that he had frequented the spectrum and purchased ammunition there over the preceding two years.

Ison stated that officers found a cellphone in a mall toilet that they suspect Sapirman planted there. At Sapirman's flat, they discovered a laptop and a can of butane inside an on, high-temperature oven, the chief stated without elaboration.

The FBI will analyze the broken mobile phone and laptop, and "we are very curious to see the results," he said.

Mark Myers, the mayor of Greenwood, an approximately 60,000-person city located south of Indianapolis, stated that the grieving community is surprised to be the site of a mass shooting.

"I do not wish to be one of the mayors required to share these sentiments. But tragically, I am," he remarked. "I grieve for these senseless murders and the scars left on the victims and our community," she said.