A soldier killed his friend's father after suffering a manic reaction to cannabis, a court has heard.
Laurie Draper, of Roman Barracks, Colchester, Essex, attacked 53-year-old teacher Paul Butterworth at his victim's home in Hoddesdon, Herts, on March 7, St Albans Crown Court was told.
The 30-year-old's not guilty plea to murder was accepted by prosecutors on grounds of "diminished responsibility" after medical tests found he was suffering from hypomania causing "cannabis-induced delusions".
He broke down in tears in the dock after admitting the lesser charge of manslaughter and also assaulting Mr Butterworth's son, Ashley.
Ann Evans, prosecuting, said: "There's no suggestion that even shortly before the act that there was any ill-feeling between the parties at all.
"This seems absolutely exceptional."
That was why, the lawyer said, the Crown considered the charge of murder "inappropriate".
Stephen Atkinson, defending, said the defendant was "of hitherto good character".
Sentencing was adjourned until the week beginning September 25 so reports can be prepared for mitigation.
