A couple who were killed in their home as their children were asleep upstairs may have been involved in rows over parking, residents said.
Jennifer and Stephen Chapple died at their home in Norton Fitzwarren, Somerset, at 21:45 BST on Sunday.
Residents described the couple as "very friendly" and said although it was a quiet neighbourhood, there had been disagreements over parking.
Two men, aged 34 and 67, were arrested on suspicion of murder.
The older man has been released under investigation and police have been granted more time to question the younger man.
The couple's two sons, aged five and six, were unhurt and are now being looked after by family members, Avon and Somerset Police said.
A post-mortem examination confirmed Mrs Chapple, 33, died of multiple stab wounds.
Investigations into the cause of death of her 36-year-old husband are ongoing.
Mr Chapple taught computing at the nearby West Somerset College. Head teacher Gregg Mockridge said he will be "sadly missed".
"Steve was a fantastic colleague at West Somerset College, a brilliant teacher that cared deeply about the students in his care," he said.
Mrs Chapple worked in the coffee shop at a garden centre in the village, where staff said they were "devastated" at the loss of their "much-loved friend".
Taunton MP Rebecca Pow said it was "absolutely tragic and shocking" to hear the news.
She said: "It's a very close knit community so it is really devastating news. I'm sure it would have shaken them to their foundations."
Due to prior contact with the couple, Avon and Somerset Police has referred itself to the Independent Office for Police Conduct (IOPC).