The attorney for 19-year-old Peter Weida says his client was mentally ill when he attacked a female high school student at a Lancaster home in March.
Robert Beyer says in a court filing last week that a number of witnesses would testify that Weida began acting strangely about a month before the attack. The Intelligencer Journal/Lancaster New Era reports a psychiatrist told the court Weida hallucinates and is in denial of his mental illness.
Authorities say the Shippensburg University student attacked an 18-year-old Lancaster Country Day student with a meat cleaver without provocation.
The teen underwent surgery for her injuries.