A jury has unanimously convicted a Kerry man of murdering his 75-year-old mother, rejecting his claim that he should be found not guilty by reason of Insanity having Strangled her at her home three years ago while suffering a manic episode related to Bipolar Disorder. The jury accepted the prosecution’s case that the cause of 55-year-old Billy Burns killing his mother Miriam Burns was not mental illness but his “long-term abuse of Drugs and Alcohol” and anger towards his Mother.