Detectives say a woman whose body was found in a burning car may have known her killer.
A murder inquiry was launched after the remains of 23-year-old Catherine Wells-Burr were discovered in a red Ford Focus car by firefighters on Wednesday.
Fire crews were called to reports of a car on fire in a lane in Ashill off the A358 near Ilminster, Somerset, shortly before 6.30am.
Detective Chief Inspector Simon Crisp, of Avon and Somerset Police , said one theory was that Ms Wells-Burr knew her killer.
He said police planned to speak to friends and associates of the graduate business analyst, and anyone else who may have any knowledge of her social and private life.
"One of the theories is that she knew her killer, anything is possible and you dismiss things at your peril," he told reporters at a news conference on Thursday.
"I am making a double appeal today. Firstly, for those people that may have witnessed Catherine and her red Ford Focus arriving at the scene which is alongside the A358 near Ilminster.
"Did anybody see that car arrive? Did anybody see suspicious people arrive or leave the scene at about 6am to 6.30am on a busy road? We need you to call us.
"The second part of the appeal is to help us understand Catherine's private and social life.
"Did she know her killer is the question that we're asking ourselves. Did she arrange to meet somebody at the location where she met her death? These are the things we are seriously considering.
"We are working on the theory that she possibly knew the attacker. We do not think this is a random attack but we are not ruling it out."
Ms Wells-Burr, from Chard, Somerset, graduated with first class honours from Bath Spa University.
On August 25, she updated the cover photo on her Facebook profile with a picture of a woman covering her face with a book.
Accompanying the picture was the cryptic message: "You can't start the next chapter of your life if you keep re-reading the last one."
Maurice Hicks, headteacher of Holyrood Academy in Chard where Miss Wells-Burr was a former pupil, spoke of his shock at the news.
"Everyone at Holyrood Academy is deeply saddened and shocked to hear the news about Catherine," he said.
"She is warmly remembered as a very friendly young person, gregarious and with a great sense of humour.
"Catherine always had a smile and a positive outlook. She was very popular with the other students and had lots of friends.
"Our sincere condolences go to her family and friends at this difficult time."
Friends also took to social network sites to pay tribute to her.