The father of an 11-year-old girl found dead over the weekend is under arrest in hospital under suspicion of her murder.
Rebecca Thompson's mother found her dead at the family home in Bushey, two miles east of Watford, around midday on Saturday.
Detectives are currently examining the house for evidence, and a post-mortem examination will take place on Tuesday.
Earlier that day, her father Simon crashed his Volkswagen Golf into a roundabout at high speed in what is believed to have been a suicide attempt. He was alone in the car.
A Hertfordshire Police spokeswoman told the Evening Standard the 52-year-old was expected to be in hospital for some time and would be interviewed once deemed fit by medical staff.
One neighbour told the newspaper: “Simon doted on his daughter.
“He worked from home and spent a lot of time just sitting in his car in the driveway.
“They were a very private family. While most of the children in the street played with each other. Rebecca was not one of them. I don't think she ever had any friends round. They did not have any other children.”
Detective Inspector John Arthur, from the Bedfordshire, Cambridgeshire and Hertfordshire Major Crime Unit, said: “The death of a child is always tragic and understandably many people will be devastated and concerned by what has happened. Our thoughts are with Rebecca's family and friends at this terrible time.
“I have two key appeals to make from the public - did you see the VW Golf which would have been driven at high speed just prior to the crash at the Elstree Hill roundabout in the early hours of Saturday morning? This is a very important element to this investigation.
“I am also very keen to hear from anyone who saw, or knows where Rebecca had been during Friday 21 June. Who was she with? Where was she and at what time?
“This tragedy comes in the wake of two deaths of local teenagers in a short time and we have in place additional patrols and resources in the area to support the community and these will remain in place for as long as necessary.”
Rita Cooper, headteacher at Sacred Heart Primary School in Bushey, which Rebecca attended, said: “It is with great sadness that we heard of the death of Rebecca who was in year six at Sacred Heart.
“Rebecca was a lovely girl who was hard working and did well in her learning. She was looking forward to secondary school.
“The whole school is very distressed by this tragedy and our thoughts are with her family and friends.”