14-year-old US girl stabs to death 'ungrateful' sister

A 14-year-old Illinois girl, who stabbed her step-sister 40 times for not being grateful, has been arrested and charged with murder, US media reports said today.

Police found the 11-year-old girl unconscious and in need of medical attention in an upstairs bedroom of the Illinois suburb of Mundelein on Tuesday. She later died.

Because the sister, who called police, initially told officers an intruder was to blame for the attack, authorities briefly placed three schools on lockdown.

The 14-year-old, authorities say, repeatedly and fatally stabbed her half sister with a kitchen knife because the teen thought she was ungrateful. "This incident is a heartbreaking tragedy that defies understanding," said Mundelein Mayor Steve Lentz. "I am asking the Chicagoland area, please pray for us. Pray, first of all, for the family that has been devastated by this."

The 14-year-old girl told police that an intruder had barged into the home, attacked her sister and then fled, said Mundelein Police Chief Eric Guenther. But the teen's story unraveled quickly. Under police questioning, she admitted to the attack, authorities said.The 14-year-old told police she was mad that her sister did not appreciate all she did for her, prosecutors said at the suspect's detention hearing yesterday.

The teen said she cooked dinner for her younger sibling and performed other chores. She was also angry that the 11- year-old girl had recently hit her. The night before the attack, the teen thought about it briefly, then went downstairs and grabbed a knife, according to prosecutors.

After the stabbing, she took a shower to wash off the blood, called police and made up the story about the intruder, prosecutors said. The 14-year-old was arrested and was charged with murder, CNN reported.

The case is in juvenile court and a decision could be made in the future to move the case to adult court, the Lake County State Attorney's Office said. Those who knew the girls said they lived at the home with their mother. Neighbours said the siblings seemed close.