Steele was chasing after him, grabbing at him and hitting the back of his head, according to Hill's report.
Body cam footage shows the moment the cop arrived at the Burlington home, in Iowa, where Steele, 34, was in a heated row with her husband Gabriel
When the officer arrived at the 100 block of South Garfield Avenue, Gabriel was walking away from the house with the couple's toddler, then aged 3, in his arms (pictured)
Steele is seen running after her husband as the officer warns the couple to stop their dog. Moments later, tries to shoot the pet only to slip and fire a shot at the woman
Hill orders her to 'Get your dog!' before letting off two shots as the camera angle suddenly skywards as he slips
Out of camera shot, Steele was heard to cry out. She was rushed to hospital but died of a gunshot wound to her stomach.
Hill later explained that he had been attempting to shoot the German Shepherd, which he claimed had tried to bite him, but had slipped and shot the woman instead.
A prosecutor later determined that Hill should not face disciplinary action for the shooting. The officer has now returned to active duty.
The Iowa Department of Criminal Investigation later released body camera video that shows the shocking moment Steele was killed.
According to a report by KBUR, Des Moines County Attorney Amy Beavers determined that the incident was a 'very tragic, accidental death,' reported WQAD.
Beavers said: 'Officer Jesse Hill's actions could be determined to be reasonable under the circumstances to protect himself from injury.'
A witness in her report had claimed that Steele was 'wailing' on her husband and they feared the incident 'was going to be a mess.'
Another noted that the dog was all 'riled' up.
Out of camera shot, Steele (pictured with her children) was heard to cry out. She was rushed to hospital but died of a gunshot wound to her stomach
But Steele's family (pictured with Autumn) refused to accept the verdict that Officer Hill was allowed back to work and said they would continue to seek justice
Steele had only just been released from Des Moines County jail where she had spent the night after being charged with domestic assault on her husband the day before
'Based upon my review of the case with the Iowa Division of Criminal Investigation and a full review of the facts and circumstances provided to me concerning the death of Mrs. Autumn Steele, it is determined that no criminal charges against Officer Jesse Hill are supported by the evidence,' she wrote in her ruling.
'Officer Hill was faced with the decision to shoot in an instant. He had to process the situation alone, and made the decision at the time the threat was occurring.'
But Steele's family refused to accept the verdict and said they would continue to seek justice.
Earlier this year, the Burlington community held a rally for the mother via her family's Facebook campaign site.
Since the release of the body cam footage, the family have also been campaign for the release of further details relating to the case.
An Iowa regulatory board agreed earlier this month to decide if records and dashboard video of the shooting must be made public.
'It was such a long road to just get here,' said Gina Colbert, Steele's mother. 'We wanted somebody to listen and they're listening now and finally hearing. We're not being told no anymore. We're not being ignored.'
The family have sought 911 call transcripts, emails and dashboard camera footage.
Officers attended the scene after the accidental shooting of the mother-of-three at her home in Iowa
A prosecutor later determined that Hill should not face disciplinary action for the shooting. The officer has now returned to active duty
Steele, a dental technician who loved the outdoors and hiking, is survived by her husband, Gabriel, two sons, Gunner Steele and Kai Schoff, both at home and step-son, Devin Steele.
After her tragic death, her family wrote Steele 'had a beautiful smile that attracted Gabriel to her and her inner beauty matched her outer beauty.
'She was a devoted wife, mother and sister. She was a family caretaker and lived for her children.'
The family dog, a 7-year-old German shepherd-collie mix named Sammy, was shot once in the right shoulder but was taken to a local vets and recovered.
An animal hearing board voted unanimously that the dog wasn't dangerous and he was returned to his owners.