A British man murdered alongside his wife and mother-in-law on holiday in the French Alps moved his family from one campsite to another two days before they were gunned down.
A Dutch couple believed the group planned to spend a week at the three-star Village Camping Europa site in St Jorioz but they left after a two-night stay.
The campers said father-of-two Saad al-Hilli acted strangely during that time, leaving his family alone several times each day.
They also noticed an unusual man wearing a smart jacket visiting while the al-Hillis were there.
The family moved into neighbouring site Le Solitaire du Lac last Monday before the brutal attack in a remote spot close to Lake Annecy on Wednesday afternoon.
Investigators have said each victim was killed with the same gun, fuelling speculation they were targeted by a contract killer. Each person was shot twice in the head.
Detailed ballistic analysis of 25 spent cartridges found at the scene revealed they all came from a 7.65mm automatic pistol.
Sylvain Mollier, 45, a French cyclist who apparently stumbled across the attack, was also killed.
Staff at Village Camping Europa described the family as "very quiet, nice people".
A manager, who refused to give her name, said: "They came to stay with us on Saturday evening and left on Monday.
"That was pre-planned - they were here for just a few days."
She dismissed suggestions that Mr al-Hilli behaved oddly during his stay, adding: "There was nothing strange. All families leave the campsite at all sorts of times to run errands, go to the shop, organise activities, that sort of thing."
And she said comments about a mysterious man described as appearing "to come from the Balkans" were "ridiculous".
She said: "That was an Italian man who was here. He left and got on his plane as was planned."
The bodies of Mr al-Hilli, 50, from Claygate in Surrey, his dentist wife Iqbal and Mrs al-Hilli's mother were discovered in their bullet-ridden BMW in a secluded car park in the Combe d'Ire forest, near Chevaline, just a few miles from Le Solitaire du Lac.
The al-Hillis' two daughters survived the horrific attack.
Seven-year-old Zainab - who was shot and so brutally beaten that doctors placed her in a medically-induced coma - is now seen as one of the key witnesses.
Police spoke briefly with her after she regained consciousness on Sunday and are waiting for approval from medics before they can question her further.
Her younger sister Zeena, four, escaped unscathed by cowering behind her mother as bullets rained down. She has flown back to Britain with carers.
French police are examining two mobile phones found in Mr al-Hilli's car and are understood to be examining the hard disk for a laptop.
British officers are working with their French counterparts to try to unravel the mystery surrounding the four deaths.
Yesterday, the spotlight turned on the al-Hilli family home after police identified items of apparent concern and called in a bomb disposal squad from the Royal Logistic Corps.
Neighbouring properties were evacuated as experts examined the mock-Tudor house, focusing on a shed at the bottom of the garden. But officers later said that the unidentified items were not hazardous.
Detectives were today continuing their search of a safe which had to be opened using power tools.
Police are examining all aspects of Mr al-Hilli's life to try to find a motive for the murders, looking at his personal and professional links which include work for a satellite technology company in Surrey.
Investigators have disclosed that his brother, Zaid Hilli, approached UK police to deny any feud with his sibling over an inheritance.