A 15-year-old boy was arrested Friday afternoon for the murder of a 68-year-old woman in her home in Vyronas, eastern Athens last week, police said Saturday.

Laura Demenikioti’s body was found Thursday night with two stab wounds to the heart.

Police said the boy, a high school pupil who lived in the same apartment building as the victim, confessed to the crime after being taken in for questioning, giving robbery as his motive. According to reports, he stole 350 euros.

Police realized Deminikioti must have known her assailant, as there were no signs that the apartment had been broken into.

Neighbors expressed astonishment at the boy’s arrest, saying they had never known him to have been in any trouble.