The killer of a French student who was murdered in a south-west London park may have been lying in wait for his victim, police said.
Police are confident the victim was not followed from the bus stop
Officers think 22-year-old Amelie Delagrange's attacker may have hidden behind two cricket sight screens in Twickenham Green on Thursday.
The screens are being removed for forensic examinations.
Ms Delagrange died from head injuries and a possible link to three similar attacks on women is being considered.
Firefighters brought in heavy cutting equipment to remove the screens which will undergo light sourcing treatment to see if any trace of the attacker has been left behind.
RECENT ATTACKS IN THE AREA
1: 8 January 2003, 17-year-old girl attacked
2: 4 February 2003, Marsha McDonnell, 19, killed
3: 18 April 2004, 34-year-old woman attacked
4: 19 August 2004, Amelie Delagrange, 22, killed
Detective Chief Superintendent Andy Murphy said: "It's possible he could have
been hiding behind the sight screen, it's certainly something we are exploring."
Police are confident the victim was not followed from the Fulwell Bus Garage where she got off a bus at about 2150 BST.
CCTV footage of Ms Delagrange getting on the 267 bus outside the Wetherspoon's pub on London Road has been released by police in the hope it will jog someone's memory.
Police have been looking into possible links with the murder of Marsha McDonnell, 19, was bludgeoned to death three miles away from the scene in February 2003.
A 17-year-old girl was also left with serious head injuries after an attack in Twickenham in January 2003.
And 34-year-old Edel Harbison also suffered a head injury while out walking near Twickenham Green in April.
A 16-year-old arrested in connection with the death of Ms McDonnell is being detained under the mental health act.
He was still in custody when Ms Delagrange died.
Detectives said the killer may be a local man, aged between 15 and 30.
They are warning women to take care while out walking and to stay in well-lit, busy places.
Officers also want anyone who was in the area on Thursday evening to come forward.