Forensics officers have locked down a neighbourhood in western France, searching for traces of a family that disappeared, leaving behind a bloody mobile phone, stripped beds and a home where "time froze".
The disappearance of the Troadec family has eerie echoes from the past, down to the missing computers and the hasty attempts to scrub away DNA evidence.
For six years, investigators in the city of Nantes have been haunted by the deaths of another local family, and have been searching for the father, who is suspected of killing his wife and four children.
In the latest case, Nantes prosecutor Pierre Sennes told Europe 1 radio that the hope is to "intensify the assessment of what could have happened in the house".
A nationwide police bulletin on the family said initial suspicion had fallen on the couple's 21-year-old son, "suspected of having a deadly plan to kill the members of his family and perhaps himself".
Traces of blood from the parents, Pascal and Brigitte, and from son Sebastien, were found on the staircase and ground floor during an initial search on February 23 in the parents' home in suburban Orvault.
Sebastien Troadec's Peugeot is the only car missing, and his bloody mobile phone was found in the house.
A jogger found his 18-year-old sister Charlotte's health card and her trousers in a ditch more than 270 kilometres (168 miles) away on Wednesday, according to the Le Parisien and Ouest France newspapers.
Sebastien's phone, like the other phones of the family, has gone unused since February 17.
The beds were stripped and there were no toothbrushes in the bathrooms.
Dishes cluttered the sink, while a load of wet laundry filled the washing machine.
Mr Sennes opened a murder investigation in the case this week after investigators spent the weekend searching for clues.
"It's like time froze in the house," he said on Sunday.
According to the local newspaper, Ouest France, the family's electronic devices were missing, but the person who took them left behind their charging cables.
This was also the case in the killings blamed on Xavier Dupont de Lignonnes, whose wife and four children were found buried beneath their porch in 2011, less than four kilometres from the Troadec home.
The oldest of those children was a student at the same school as Sebastien, Ouest France said.
De Lignonnes has never been found.
French national television aired a documentary about the case in January, in which his best friend speculates that he started a new life abroad.