A 3-year-old boy was murdered by his teenage 15-year-old sister, who used his blood to write a chilling message to their mother on a wall.

Olivia, the 15-year-old half-sister of the 3-year-old boy, is accused of stabbing Nicolas, her toddler brother, to death.

She reportedly wrote “This Is Your Son” in his blood on a wall.

The girl stabbed her younger brother 28 times while he slept.

The incident happened in Detmold, Germany.

She left the house after murdering the boy.

Agnieszka, the mother of the child, came home to his dead son and informed the police right away.

The police tracked down the girl 6 miles away from her house after a helicopter was used to hunt her down.

Olivia is now facing 10 years in youth detention if she gets convicted in murdering her 3-year-old brother.

Agnieszka and her family moved to Germany in 2013. She is originally from Lodz, Poland.

During an interview with the press, Agnieszka said:

“When I saw his body in the bed I thought at first he was sleeping, I stroked his hair and then I realized he wasn’t sleeping. He was dead.”

The mother, who is 46-year-old, also told the press that she is willing to forgive her daughter.

Explaining her reason, she said:

“She is my child. I would never leave her alone. I love her over everything, just like my son Nicolas. I want to stand by her side and to hold her in my arms.”

Dimitri, the ex-boyfriend of Agnieszka, said:

“Agnieszka and I had separated three months before – Olivia was jealous of the little one and felt left out.”

Olivia, the 15-year-old, was known for frequently babysitting her younger brother.

The mother was shocked after the incident, realizing that the teen had so much hatred against her brother.