Mall gunman fired 24 times in 15 seconds

A 20-year-old man who shot five people in a US shopping centre, killing three of them, fired 24 times within 15 seconds before he was shot and killed by an armed bystander, authorities say.

Preliminary autopsy results show gunman Jonathan Sapirman was shot eight times during his attack on Sunday at the Greenwood Park Mall in suburban Indianapolis, Indiana.

None of the gunshot wounds was self-inflicted, the Johnson County Coroner's Office said.

Also, Greenwood Police Chief James Ison issued a statement on Tuesday saying surveillance video showed Sapirman was shot within 15 seconds of opening fire, not within two minutes as the chief had said at a news conference on Monday.

Ison blamed the timing error on misreading his notes during the news conference.

Sapirman continued shooting people at the shopping centre on Sunday evening until he was shot and killed by 22-year-old Elisjsha Dicken.

Dicken was shopping with his girlfriend at the time, Ison has said, calling Dicken's quick action "nothing short of heroic".

The Johnson County and Marion County coroners' offices identified the slain victims as a married Indianapolis couple - Pedro Pineda, 56, and Rosa Mirian Rivera de Pineda, 37 - and Victor Gomez, 30, also of Indianapolis.

A woman shot in the leg and a 12-year-old girl who was hit by shrapnel to her back were wounded in the attack, police said.