'Hero' four-year-old girl kept her two-month-old baby brother alive for three days as their parents lay dead nearby after their father 'shot their mother then turned the gun on himself'

A four-year-old girl has been hailed a hero after she kept her two-month-old brother alive for three days after their father shot dead their mother before turning the gun on himself.

A neighbor discovered the two young children unharmed but dehydrated and hungry downstairs at the family's home in the Chatsworth neighborhood of Los Angeles on April 14 as their parents' lifeless bodies sat in an upstairs bedroom.

A medical examiner identified the father as 46-year-old David Kooros Parsa and mother as 38-year-old Mihoko Koike Parsa.

Investigators determined that the murder-suicide likely took place three days prior on April 11.

'Our little angel was able to keep herself and her brother alive,' Los Angeles Police Captain Maureen Ryan said of the four-year-old.

'The baby is a miracle baby and the little girl is a hero. She's an absolute hero.'

At a news conference on Tuesday authorities said the children are in the custody of the Department of Children and Family Services and are in good health.

On the day that the bodies were discovered, police went to the property at 9am in response to a welfare check request from a family member, but they left after finding nothing amiss.

Hours after the cops' departure, a family friend of the couple's came by accompanied by a locksmith, and together with neighbors they gained access into the home and discovered the carnage inside.

Olivia and James Robinson, who live across the street from the deceased couple, told KTLA they knew something was wrong when they found the four-year-old downstairs.

'She obviously was in bad condition because she reeked really bad of urine,' Olivia said. 'And she had more of a blank stare on her face. She was very, very quiet.'

The neighbor said when the child was asked about her parents, she said they are sleeping, then added that they are upstairs and are hurt.

Another neighbor, Tony Medina, took in the four-year-old into his home and offered her food until police arrived.

'She heard her mom crying, and then what really was kind of heart-wrenching was when she said she saw "mommy was broken,"' Medina told CBS Los Angeles.

Their two orphaned children were taken into the custody of the Los Angeles County Department of Children’s Family Services.