Murdered landscape architect Jo Yeates probably knew her killer, her heartbroken parents said today as they made a desperate plea for help.
David and Theresa Yeates urged anybody who knew somebody who had reacted strangely to the murder to come forward.
They said: "It would appear that the nation is shocked and appalled by what has happened to our daughter.
"Do you know someone who has been, somehow, justifying her being killed?
"Please help us identify the killer. Jo was probably acquainted with her killer."
Mr Yeates, 63, and his wife, 58, said they spent much of their time thinking how their daughter could have ended up dead by the side of a country lane.
They called on other "armchair detectives" to think about whether they had information which could help with the investigation.
Miss Yeates's snow-covered body was found on Christmas morning by a couple walking their dogs in Longwood Lane in Failand, North Somerset. She had been strangled.
The 25-year-old went missing on the night of December 17 after leaving friends in the Ram pub in Park Street, Bristol.
Reading a statement at the Thistle Hotel in Bristol, her parents said: "Many of us are 'armchair detectives', but if this activity triggers anything please come forward.
"If you do know something and you do not come forward you are consciously hampering the apprehension of Jo's killer(s) and the perpetrator(s) is still free.
"You will also be prolonging the torment of Jo's family and friends."
Mr and Mrs Yeates were joined by Miss Yeates's brother Chris, 28, and boyfriend Greg Reardon, 27.
The parents, who said they were sure the killer would be brought to justice, continued: "Do you know anyone that hasn't been shocked or disturbed?
"Has anyone you know had an unusual or inexplicable reaction?
"Was their behaviour unusual on the weekend of 17/18/19th December, or throughout the past three weeks?"
Miss Yeates lived with Mr Reardon in a sunken ground-floor apartment in a large converted Victorian house in Canynge Road, Clifton.
A floorplan obtained from the Land Registry showed her killer could have entered and left her flat without being seen by any of her neighbours.
The only way into the self-contained apartment is through a private front door down a side path.
Detectives have established that Miss Yeates returned home on the night she disappeared a month ago, but they are still investigating how her body came to be dumped in a country lane three miles away.
Her coat, boots, mobile phone and keys were found in the flat, but no trace has been found of a Tesco pizza she bought on her way home.
The floorplan, dating from 1990, shows there was previously a door from Miss Yeates's bedroom to a bedroom in the adjoining flat, but it was filled in when the building was converted.
There is a communal entrance at the front of 44 Canynge Road for most of the other flats, but a second ground-floor apartment also has its own front door at the rear of the property.
Miss Yeates and Mr Reardon rented the flat from Chris Jefferies, 65, a retired English teacher at nearby Clifton College, who was arrested on suspicion of the murder before being released on bail.Reuse content