Police accuse the man of striking his 50-year-old sibling with the hammer and punching her after a dispute at a Turnatt Way home on May 4.
Acting Senior Sergeant Stuart Fairlie said the woman ran but collapsed outside the house.
“Passers-by stopped to help her and she was taken to Joondalup Health Campus for treatment,” he said.
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READ NOWThe woman needed four stitches for a cut to her head.
Investigators charged the alleged offender the next day with aggravated assault occasioning bodily harm and aggravated unlawful wounding.
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