A 38-year-old woman killed after her five-year-old son got ahold of a handgun and accidentally shot her in their Arizona home on Friday.

Casa Grande police say Michele Cox had been shot in the chest around 6.20am while her four children, ages 4, 5, 11 and 12, and boyfriend, 40, were home.

She was life-flighted to a nearby hospital where she died from her injuries.

Although police initially ruled the shooting accidental, her brother, Michael Cox, is seeking justice for his sister.

‘I would really love for the person responsible for having the gun to be prosecuted,’ Michael told  KPNX.

‘In the event that is the truth, that her 5-year-old picked up a .45 caliber and shot it at his mother, somebody still should be prosecuted for negligence for even having a gun at all,’ he added.

Investigators have not yet determined who the weapon belonged to and no one has been charged in the case.

Casa Grande Police say they are continuing to investigate the incident and are working with Pinal County Attorney’s office to determine if any crime occurred.

MailOnline has contacted the law enforcement agencies for comment.

Meanwhile, Cox’s four children were placed in the care of her father. They are reportedly very upset by the situation.

‘All of the kids are distraught, and they really just don’t know what’s next, so we’re doing the best to support them,’ Michael said.