An 18-year-old girl has been arrested for allegedly murdering the 3-month-old daughter of a woman she lived with in Tokyo, police said Tuesday.
The girl, from the city of Nagano, is suspected of strangling the baby on Nov. 1 at their apartment in Shibuya Ward.
The girl, who was handed the arrest warrant Friday but has been in custody over the case since November, has denied the charge, the police said.
The girl started living with a 21-year-old woman, her baby and another 18-year-old girl around August last year and took care of the baby when the mother was away, according to the police.
They suspect the girl was regularly abusing the baby.
The incident originally came to light after the other girl reported to police on Nov. 1 that the baby might be dead. The police arrested the two girls on Nov. 15 on an assault charge for allegedly covering the baby's mouth. The two have been held in a juvenile reformatory.
The girl arrested for murder says the baby was already dead when she woke up that morning, but an autopsy found that the baby died from suffocation.
She told the police during interrogation that she enjoyed seeing the baby in pain. Security camera footage in the apartment showed that the girl was alone in the apartment with the baby at the time of the baby's death, according to police.
The police believe photographs found in a trash bin at a nearby convenience store show the baby being abused.
The suspect's name is being withheld because she is a minor.