BLOOMINGTON, Ind. (AP) — A 19-year-old man has been sentenced to eight years of house arrest after pleading guilty to attacking a 13-year-old girl in 2019 as she was attending an Indiana University violin camp.

Dongwook Ko, who was 17 at the time of the attack, was also sentenced Wednesday to two years of probation and ordered to get psychological treatment.

The Herald-Times reports the girl’s mother says she’s disappointed Ko didn’t receive prison time, saying her daughter was denied justice.

Ko had pleaded guilty to criminal confinement while armed with a deadly weapon for the July 2019 attack in which he attacked the girl with a pocketknife, leaving her with cuts.