The baby is being held in a Tulsa, Oklahoma, juvenile detention facility, in line with a Tulsa Police news launch.
Officers responded to a stabbing late Thursday evening, the discharge mentioned.
When officers arrived, paramedics and firefighters “were already on scene and performing CPR to a nine-year-old male victim,” police mentioned.
“Officers learned the children’s parent was upstairs asleep when the 12-year-old daughter woke the parent up and said that she had stabbed her nine-year-old brother,” the discharge mentioned.
The boy “was rushed to the hospital and taken into surgery,” however succumbed to his accidents shortly after 2.30am native time, in line with police.
The 12-year-old suspect was taken into custody and is being held on the Family Centre for Juvenile Justice, mentioned the news launch.
Neither baby has been recognized by authorities.
The Tulsa Police Department Child Crisis Unit is dealing with the stabbing investigation.
This is the second murder within the metropolis of Tulsa this yr, the division mentioned.
