( CNN ) -- A 17-year-old Connecticut high school student pleaded not guilty Wednesday in the slashing death of a classmate in a school stairwell in April , a court official said . Christopher Plaskon appeared in Milford Superior Court , where he waived his right to a probable cause hearing and elected to be tried by a three-judge panel rather than a 12-member jury , according to clerk Linda Kautzner . His attorney , Richard Meehan Jr. , told CNN that he is considering a mental health defense . Plaskon is suspected of slashing classmate Maren Sanchez , 16 , at Jonathan Law High School in Milford on April 25 . He was 16 at the time . A witness saw Plaskon on top of the victim and tried unsuccessfully to pull him away , according to a probable cause statement in the case . Another witness allegedly saw him discarding a bloody knife in a school corridor . The state medical examiner 's office concluded that Sanchez died from `` stab wounds to the trunk and neck '' and ruled the death a homicide . Though the motive remains under investigation , police were looking into whether the boy was angry after Sanchez rejected him as a prom date . `` I did it , '' Plaskon allegedly told a school police officer in the principal 's office moments after the crime , according to the probable cause statement . `` Just arrest me . '' Plaskon was ordered held on $ 3 million bond in April . He was charged as an adult and faces 25 to 60 years in prison if convicted . His next court appearance is July 30 , Kautzner said .
Christopher Plaskon , 17 , was charged with murder as an adult in the slaying of a classmate . Maren Sanchez , 16 , died after being stabbed in a school stairwell on April 25 . Comment: