article_snippet: A retired teacher knocked A retired teacher out with a dumbbell and then slit A retired teacher in a 'mercy killing' at their £390,000 home because A retired teacher couldn't cope with A retired teacher dementia, a court heard.
article_snippet: In May last year Mr Bennett decided Mr Bennett wanted to 'end A retired teacher pain' and severely struck Mr Bennett with several blows to the head with a dumbbell fracturing His devoted wife of 55 years skull.
article_snippet: Mr Bennett then cut His devoted wife of 55 years throat with a kitchen knife before calmly calling 999 and telling operators: 'I've done a terrible thing, I have murdered His devoted wife of 55 years.'
article_snippet: Judge Simon Tonking said: 'This wasn't a premeditated killing.
article_snippet: He then cut her throat with a kitchen knife before calmly calling 999 and telling operators: 'I've done a terrible thing
article_snippet: , I have murdered His devoted wife of 55 years'
article_snippet: I can't believe it was murder, He was probably trying to help murder die. '
highlights_snippet: Retired teacher knocked wife out with a dumbbell and  slit wife throat in a 'mercy killing'
  Mr Bennett then calmly called police and said: 'I have murdered my wife'
  Retired teacher has been detained in a psychiatric clinic under the Mental Health Act .