A dad was drowned at a members-only fishing lake by a schizophrenic stranger who wrongly believed he had assaulted his mother.
Kevin Hodkinson, 50, was reported missing after members noticed his equipment and car were still present and reported a man behaving suspiciously in the area.
The dad-of-three's body was found in Oxspring Dam, a private pond in Sheffield, South Yorkshire, on June 16 last year.
But officers guarding the scene later arrested Kieran Hayes, 33, who lived near the fishery, after he was spotted running past the scene with bare feet.
He was charged with murder, but prosecutors accepted a guilty plea to the lesser charge of manslaughter on the grounds of diminished responsibility.
Hayes was given an indefinite hospital order at Sheffield crown court earlier this week.
The court heard Hayes, who lived near the fishery, had been diagnosed with paranoid schizophrenia.
He began to hallucinate that Kevin was another person who he wrongly believed had assaulted his mother, the court was told.
He then pushed him into the lake and drowned him. Hayes was seen acting strangely by another man, who then called the police.
At a hearing on Friday, the Recorder of Sheffield Jeremy Richardson KC said Hayes remained a risk to the public.
The judge said: "This was an entirely deliberate act. But for the mental condition of the defendant this would have been a clear case of murder.
"The conduct of the defendant amounted to an intention to kill the deceased.
"It's pertinent to note that the defendant, it appears, had taken crack cocaine at the relevant time.
"There's no doubt that he was in a delusional state as a result of paranoid schizophrenia.
"There can be no doubt whatsoever that the defendant will need life-long treatment.
“In my judgement, there is really only one just conclusion in this case...that this defendant should be detained in a mental institution.
"This is wholly likely to be a life-long order. Indeed, at present, I cannot envisage the circumstances when this man will be safe to release into the community.
"The public should be, therefore, reassured that this highly dangerous man will be kept out of harm's way."
Kevin, who had represented Great Britain as a junior angler, was described by his heartbroken family as a devoted father, uncle and grandad.
Paying tribute to his "baby brother", Mark Hodkinson said: "He was a quiet, personal person with a dry witty sense of humour and was incredibly kind and caring to his family and friends.
"Those who knew him and were lucky enough to have him as a friend had the most loyal friend you can ever wish for.
"We all miss him dearly and will never again see his cheeky smile, hear his voice, share new memories and laughter, or enjoy his unwavering love, support and friendship he gave us.
"He was caring, kind and outgoing to all who met him. We love and miss Kevin every day, from the moment we wake up to the moment we go to sleep.”
Speaking after sentencing, detective chief inspector Emma Knight, of South Yorkshire Police, said: "Kevin Hodkinson was a skilled fisherman and had represented his country at a sport he loved.
"His untimely death in such tragic circumstances has devastated his family and my thoughts are with them today following this court hearing.
"Kieran Hayes has accepted responsibility for his actions in causing the death of another and has pleaded guilty to manslaughter, which has been accepted by the court."
Hayes was given an indefinite hospital order under Section 37 and Section 41 of the Mental Health Act.
