A shooting at a mall in Greenwood, Indiana, on Sunday evening has left at least four people dead, including the suspected gunman — who police say was shot by an armed bystander.

The latest: Authorities said Monday at a press briefing that a 12-year-old girl was among two people wounded after the shooter opened fire with a rifle at the mall, south of Indianapolis. Her injuries were minor, while the other injured victim received a gunshot wound to the leg and was in a stable condition in a local hospital.

Greenwood Police Chief Jim Ison said Monday that the suspected gunman, 20-year-old Jonathan Douglas Sapirman of Greenwood, was killed shortly after opening fire by a bystander, identified as Elisjsha Dicken, 22, who was armed with a handgun.

• Ison said the suspected gunman brought two AR-15-style rifles, a handgun and more than 100 rounds of ammunition into the mall but only used one of the rifles during the shooting.
• The police chief said the gunman stayed inside of a mall bathroom for over an hour before exiting and shooting a man outside of the bathroom and a couple eating dinner in a food court.
• Police have not yet established a motive for the shooting. The suspected shooter left behind a cellphone in a toilet in the bathroom, and police were serving a search warrant on his apartment on Monday afternoon.
• Ison identified those killed as 56-year-old Pedro Pineda, 37-year-old Rosa Mirian Rivera de Pineda and Victor Gomez, 30.

Driving the news: Police received reports just after 6 p.m. that a gunman had entered the food court and began shooting, Ison said at a news conference on Sunday.

• "It appears that he had a rifle with several magazines of ammunition," the police chief added.
• Ison later confirmed that a 22-year-old armed bystander from nearby Bartholomew County shot the gunman.

The big picture: The mall violence is the latest in a series shootings to rock the U.S. in recent weeks — including massacres in Buffalo, New York and at Uvalde, Texas, elementary school, which spurred Congress to pass gun safety legislation.

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Editor's note: This article has been updated with new details throughout.