The 12-year-old boy tried to be funny when he ran into his half-sister's bedroom with a laundry basket over his head.
But police say 18-year-old Willesha Shannon didn't laugh – instead, she stabbed him.
Shannon, who was arrested in 2008 on assault charges, now stands charged with aggravated battery and child abuse.
According to an arrest report, police rolled up to the home on East Atlantic Drive in Boynton Beach on Monday and found a father and his son standing in the driveway.
The 12-year-old son had a cut on his shoulder, an abrasion on his forehead and several scratches on his back. Detectives then tried to piece together the story:
Shannon and her cousin were watching a movie in her bedroom when her half-brother ran into the room.
He had a laundry basket on his head, trying to be funny, the report says.
But to Shannon and her cousin, the antics weren't very cute. Shannon yelled and tried to make the boy leave. He wouldn't, and an argument ensued.
The two began to fight.
Shannon knocked the boy to the floor and kicked him in the side of the head while he was on the ground. She scratched his back several times.
Sometime during the struggle, Shannon allegedly grabbed a knife from the kitchen and stabbed the 12-year-old in the shoulder.
That's when the boy's brother stepped in and grabbed him, dragging him into the bedroom and locking the door behind them.
But Shannon wasn't done. Police say she kicked the door open.
Afraid, the report says the boy then grabbed a machete to defend himself. That's when someone in the house called police.
Detectives found the knife, machete and damaged door. They photographed the boy's battle-beaten body.
They then arrested Shannon and booked her into the Palm Beach County Jail without bond.
In an interview with detectives, Shannon said she only grabbed the knife to defend herself against her 12-year-old half-brother.
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