Some family members say Jesus Nunez was teasing the dogs, others say the dogs were biting him, when he pulled out a handgun. It fired right into his sister's face hitting and killing her.
Witnesses who saw the homicide have different versions of what happened last March at a Parlier home.
The defendant's fiancé, Analia Sandoval said, "He was a pretty vicious dog, like he was growling with his pink gums and he was trying to bite him."
Some say Jessie Nunez was taunting at least one loose pit bull, but others say the dog was biting him when Fresno County sheriff's deputies say Nunez grabbed a gun from his waistband.
Deputy district attorney, Tim Galstan said, "A few moments later the Parlier Police Department arrived and after they arrived the defendant shouted out, I didn't shoot, the gun fell out of my pocket."
Defense attorneys say Nunez was being harassed by menacing dogs when he first threw a stick or tool at one dog, then reached for his gun.
Mark Siegel said, "His intention at this point is to shoot, not even the dog, its to show it to the dog, to discourage the dog, to ward off the dog, but at some point while he's taking his gun out of the waistband, it all happens very fast, it discharges in his hands."
The victim's two daughters took the stand, at times getting emotional about watching their mother reach for her face before she hit the pavement.
Danielle Casas said, "From what I remember, she fell on me. She fell on my leg."
Jessie Nunez wiped away tears listening to testimony about the moments following the shooting. Several witnesses testified Nunez rushed to help his sister after the shooting, they described him as stunned and immediately remorseful.
A nine-year-old girl is among the witnesses who saw what happened and is testifying.
Jesus Nunez is facing charges of involuntary manslaughter, child endangerment and being a felon with a gun. If convicted he could spend more than 15 years in prison.