A pensioner bludgeoned his wife of almost 60 years to death before drowning himself in the bath.
Police discovered the body of retired sales rep Doreen Mann, 80, sprawled in the living room of the house she shared with husband Kenneth.
The retired factory owner, 81, was found dead upstairs face down in a bath full water wearing only his vest and underpants.
Officers took away a hammer, a craft knife and another knife from the scene at Foxroyd Lane, Thornhill Edge, Dewsbury, after the alarm was raised by a visiting mental health nurse on December 23 last year (2008].
An investigation was launched at the time by West Yorkshire Police's Homicide & Murder Inquiry Team.
But Detective Sergeant Ian Lawrie told Wednesday's inquest at Huddersfield Coroner's Court that no-one else was being sought in connection with the death of the couple, who were both born in Leeds and had been married for 57 years.
The court heard how Mr Mann became depressed after he sold his business in 2000 and from 2002 to 2005 was placed on anti-depressants, and again in 2008 after a reoccurance of the mental illness.
On December 18, 2008, he and his wife were visited by psychiatrist Dr Vinood Shukla and a psychiatric nurse, the court heard.
A psychiatric nurse came to the red-bricked home called Kendoreen, where the couple had lived for 21 years, at 2.30pm on December 23.
After getting no answer from the front door apart from the couple's barking collie dog, the nurse saw a bathroom light on and called police.
Detectives found the two knives and the hammer close to Mrs Mann's body.
Her cause of death was later found to be a blow to her head and cut wounds to her neck and forearms.
Mr Mann's corpse was found in an upstairs bathroom, face down in a full bath - his cause of death was given as self-drowning.
Barbara Moore told the inquest three weeks before her sister's death Doreen had said she feared her husband might harm her.
West Yorkshire Coroner Roger Whittaker described the deaths as a "double tragedy".
He recorded a verdict that Mrs Mann was unlawfully killed and that her husband drowned.
Mr Whittaker said he was satisfied that the balance of Mr Mann's mind was disturbed at the time of his death and "that imbalance...was present at the time of the death of his wife".
Mr Whittaker added that Mr Mann had given no indication on December 18 that he intended to harm his wife and that Mrs Mann had raised no similar concerns.
But the coroner said lessons "had been learned" by the mental health trust involved.
A South West Yorkshire Partnership NHS Foundation Trust spokeswoman said: "The Trust re-iterates its sincere sympathies to the family and others affected by these tragic deaths.
"The circumstances have been thoroughly investigated, and we are grateful to the family for their input into this.
"Sadly, we cannot change the tragic events that happened but we can learn from them and a number of changes have been made as a result."
These included: Improved systems for referrals between services and exchange of information; Improved training for staff on assessing risk; Improved record keeping following home visits.
The spokeswoman added: "The investigation findings have been shared with the family and we are continuing to offer support as appropriate."