The gunman who opened fire in an Indiana mall on Sunday evening was a 20-year-old man who brought two firearms to the building and waited inside a bathroom for more than an hour before fatally shooting three people, including a married couple, and wounding two more, officials said. 

The alleged shooter, 20, was inside a bathroom near the food court of the Greenwood Park Mall for about an hour and two minutes before he entered the dining area and fired his Sig Sauer firearm. He was "neutralized" within two minutes, but not before he was able to shoot five people, including a 12-year-old who survived and three people who were killed, Greenwood Police Department Chief Jim Ison said Monday. 

"The most puzzling piece of this puzzle is the fact that he was in that restroom for an hour and two minutes ... We believe he was getting ready."

Two people, including the gunman, were pronounced dead at the scene. Two others were transported to an Indianapolis hospital, but could not be saved. 

INDIANA SHOPPING MALL SHOOTER SHOT DEAD BY ARMED 'GOOD SAMARITAN,' POLICE SAY

The deceased victims have been identified as Pedro Pineda, 56, his wife, Rosa Mirian Rivera de Pineda, 37, and Victor Gomez, 30. 

Officials have said they believe the alleged shooter walked to the mall with two guns, one of which had been deconstructed and in his backpack. 

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The alleged shooter was wearing a "waistband holster on with several magazines." He also had a backpack that was carrying a second firearm, a rifle that was "broken down," which he left in the bathroom, and "several rounds of ammunition." Investigators determined that the alleged shooter purchased the Sig Sauer on March 8, 2022, in Greenwood. 

A BRIEF TIMELINE OF EVENTS

Greenwood, Indiana mall exterior shot, with cars and a Dick's Sporting Goods location

Police gather outside a Dick's Sporting Goods at Greenwood Park Mall (Facebook/@Ty J S)

The shooter entered the mall at a doorway near the food court around 4:54 p.m., Ison said. 

"He walks directly to the food court restroom," he continues. "One hour and two minutes later, he exits the restroom and shoots Victor Gomez outside of the restroom." 

The shooter then allegedly "points his rifle into the food court where Pedro and Rosa Pineda were eating dinner and shot both Rosa and Pedro."

The gunman then continued to fire off rounds, striking a 22-year-old woman who suffered a leg wound, Ison said. One of the gunman’s bullet fragments also ricocheted off one of the walls and struck a 12-year-old girl "who was running."

A customer looking into Greenwood Park mall

A customer checks a door on the closed Greenwood Park Mall in Greenwood, Indiana, Monday, July 18, 2022. (AP Photo/Michael Conroy)

At 5:57 p.m. – only about two minutes after he allegedly unleashed his attack – a legally armed "good Samaritan" named Elisjsha Dicken returned fire with a pistol. Dicken had been shopping with his girlfriend at the time. 

"The shooter fired several rounds, striking the suspect. The suspect attempted to retreat back into the restroom and failed – fell to the ground after being struck." 

The gunman allegedly fired 24 rounds. Dicken fired 10, Ison said. 

Ison again lauded Dicken for his life-saving response. 

"Once he came out and started shooting it was two minutes by the time the first shot was fired until he was neutralized by our good Samaritan."

Police cars outside an Indiana mall amid a mass shooting

Investigators on the scene of the crime. (Facebook/@Ty J S)

The police chief said investigators were still working to determine a possible motive. FBI forensic investigators are scouring data from his cellphone, which was wet because the alleged gunman "placed his cellphone in the toilet," Ison said. 

And police also went to the suspect’s home in the hours following the shooting, when they entered to find that "the oven was on" and there was "a laptop in the oven and a can of butane," Ison said. There was also an eviction notice posted, he added.

The alleged gunman had attended Greenwood High School and was subsequently employed, but had left his job in May. 

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"Right now we have no motive," Ison said. "His family members that we spoke to, they were just as surprised as everyone else was. They said there were no indicators that he was violent."

This is a developing news story. Please check back for updates.