Audio Captures Dramatic Moments After Omaha Officer's Fatal Shooting

The chilling audio recorded in moments after an Omaha police officer was shot in the line of duty this week has been released, and it reveals the frantic efforts to get help for the mortally wounded cop.

Officer Kerrie Orozco, 29, was shot in the chest just above her bullet proof vest on Wednesday while serving a felony warrant and later died from her injuries at Creighton University Medical Center, police said.

"Help an officer! Help an officer!" someone can be heard yelling on the recording of the exchange between officers at the scene and dispatch. The dispatcher then warns other officers the scene wasn't yet secure.

Orozco was set to go on maternity leave the next day to take care of her newborn daughter, Olivia Ruth, who was born premature and set to be released from the neonatal intensive care unit, authorities told ABC News. Orozco was back to work the week after giving birth to Olivia on Feb. 17, according to officials.

The audio was released by Mean Streets Omaha, a citizen's group that live-tweets police radio calls in Omaha. The Omaha Police Department did not immediately confirm the authenticity of the recordings to ABC News.

Orozco and two other officers were in pursuit of 26-year-old Marcus D. Wheeler on Wednesday afternoon near 30th Street and Martin Avenue, police said. He was wanted on a felony warrant for first-degree assault from a September 2014 shooting.

When Orozco and another officer pulled up to Wheeler in an unmarked car with lights flashing, Wheeler shot at the officers and then ran, Omaha Police Department Police Chief Todd Schmaderer said on Thursday night, adding new details to how the tragedy unfolded.

When officers caught up with Wheeler, he fired again, and the officers returned fire, Schmaderer said. That's when Orozco was hit by one of at least six gunshots that Wheeler fired, he said.

Wheeler was shot multiple times before collapsing in a nearby yard, Schmaderer said, and he was later pronounced dead from a lethal gunshot wound to the chest.

In the audio recordings, sirens can be heard in the background while medics report back that two patients are en route to the hospital.

Omaha Mayor Jean Stothert announced a vigil for Orozco at 7 p.m. Monday at St. John's Catholic Church at Creighton University. Her memorial is planned for Tuesday at 11 a.m. at St. John's.

The Omaha Police Department has set up a college fund for Olivia that the community can to donate to.