14year old stabs 11-yr old sister 40 times because she was not thankful

                             

A suburban Chicago teen confessed to stabbing her 11-year-old sister to death Tuesday morning because she is 'not thankful.'

Dora Betancourt had as many as 40 stab wounds across her neck, chest and arms, as well as slashes to her face. Her 14-year-old sister reportedly shouted a separate reason at her for each stab wound.

The teenage suspect initially claimed a Hispanic male had broken into their Mundelein, Illinois, home, but she allegedly confessed after police revealed they had found a strand of the killer's hair in the victim's hand.

Authorities told local media the older sister waited while young Dora slept before taking a kitchen knife and committing the grisly murder.

The unidentified older sister stabbed and slashed the young girl in a frenzied attack, shouting a reason at her sister each time she plunged the knife into her body, police said.

Stab wounds were found in the girl's neck, arms and torso, some of them defensive wounds. The young girl's body had so many wounds they couldn't count them all... [and] were so deep they punctured her lung.'

'A struggle ensued,' Assistant State's Attorney Claudia Kasten told the courtroom, according to CBS Chicago. 'She kept stabbing.'

The teen kept stabbing and slashing until Dora's body fell lifelessly off the bed and then called her mother claiming she had been woken by her sister's screams, authorities said.

The girls' mother wept during a Wednesday court hearing where prosecutors claimed that the older girl had set her alarm early and made her attack while her little sister was still in bed.

'With each stab wound, she said she was not thankful for what she had done,' Ms Kasten said,

The older girl told investigators she made dinner six times that week and that her sister made her mad after hitting her the night before.

Their mother was not home at the time of the attack, which happened just before 8:30 a.m.

The girl wore gray prison scrubs, sat stone-faced during the hearing and left quickly when it was over, as her mother sat at the same table, but without looking at her.

The sisters shared the same mother but have a different father.