The Massachusetts teenager convicted of raping and killing his high school math teacher is likely to mount an insanity defense again when he goes on trial for allegedly attacking a state youth services worker.
The Salem News reports that lawyers for 18-year-old Philip Chism told a judge Monday they anticipate filing a notice of a mental health defense and asked that he undergo a competency evaluation.
Chism faces charges including attempted murder in connection with the alleged assault in June 2014.
Prosecutors say he attacked the woman at a detention facility in Boston while awaiting trial for the October 2013 killing of Danvers High School math teacher Colleen Ritzer, when Chism was 14.
The jury rejected an insanity defense and he was sentenced to at least 40 years in prison.