A Good Samaritan was stabbed to death by a homeless woman who he allowed to stay at his house, Northamptonshire Police said.
Robert Chester was killed by Mary Cash and Karl Pound after he invited them into his home rather than let them sleep on the streets.
Cash, 39, was found guilty of Mr Chester's manslaughter by a jury at Northampton Crown Court.
Her co-defendant 51-year-old Karl Pound had previously pleaded guilty to murder at the start of their trial.
Northamptonshire Police said the 54-year-old victim welcomed Cash into his home on October 8 last year.
Mr Chester was later attacked and stabbed eight times. His body was then set on fire in an attempt to destroy evidence of the murder.
Neighbours called the fire service after spotting the blaze and firefighters discovered the victim's body in his sitting room.
Cash had denied murder and claimed that Pound stabbed Mr Chester following an argument over a £10 note, but the jury did not believe her story.