STAMFORD, Conn. (AP) - A Connecticut man accused of beating his 76-year-old mother to death nearly two years ago is preparing to go on trial.

Three judges are scheduled to begin hearing evidence Tuesday in the case of Timothy Anderson, of Stamford. The defense says Anderson was legally insane when he punched his mother, Maryann Anderson, several times. She went into a coma and died three days after the attack in March 2015.

Police said Anderson went into a rage after his mother and brother confronted him about his failure to take medication for psychological problems.

Anderson was initially found incompetent to stand trial, but was later ruled competent after receiving mental health treatment.

If he is found not guilty by reason of insanity, he could be sent to a maximum-security state psychiatric hospital.