A three-year-old girl was found hiding under a bed after it is claimed her dad went on a gun rampage, killing her mum and two sisters.
Austin Smith allegedly killed three family members because he thought his partner was having an affair.
He then shot dead the man he believed she was having an affair with, police in Phoenix, US, said.
Smith's wife Dasia Patterson, 29, was found dead alongside daughters Mayan, seven, and Nasha, five, at their home.
He reportedly spared his youngest daughter's life because she "reminded him of himself", CNN reports.
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The other two girls, it is claimed, reminded him of their mother.
He then allegedly drove to the home of Ron Freeman, who he suspected of having an affair with Dasia, and shot the 46-year-old dead.
Two other people, a woman aged 47 and a 33-year-old man, were also shot but survived.
The killings happened on Thursday night.
Dasia's mother, Cynthia Patterson, told ABC15 : "My daughter was one of the most humble in the world.
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"Sweet, honest, and wouldn’t harm anyone."
Describing her granddaughers, Cynthia said: "They were the most beautiful, sweetest children in the world."
Sgt Tommy Thompson told CNN that Smith said to investigators "the reason he shot these individuals is because in God's eyes it was all right for him to deal with someone in this manner".
Smith has been charged with four counts of first degree murder, two of attempted first degree murder and three counts of aggravated assault.
