article_snippet: Former nurse Dorothy Byrd, pictured, died from an overdose of morphine and Hydrocodone in February .
article_snippet: Frank Shuftan of The Cook County Medical Examiner's office said Mrs Byrd's death was caused by morphine and hydrocodone toxicity, combined with hypertensive and atherosclerotic cardiovascular disease.
article_snippet: An autopsy performed immediately after Mrs Byrd's death was inconclusive but further toxicology tests discovered a fatal dose of painkillers in Mrs Byrd's system.
article_snippet: Ultimately Mrs Byrd's was betrayed by a nurse.'
highlights_snippet: Former nurse Dorothy Byrd, 98, died of a morphine overdose in February .
  
highlights_snippet: Mrs Byrd's daughter visited Mrs Byrd's daughter mother on the day before Mrs Byrd's daughter was taken ill .
  