Flowers were left from an old friend for May Evans at the spot where she was stabbed to death yesterday afternoon.
The crime has shocked everyone in the normally quiet corner of Luton.
70-year-old May, who had only re-married last month after six years as a widow, was attacked while in her car at the junction of Trent Road and Solway Road close to where she lived.
Friends and family left flowers, her sister Julie Vincent said she was a very caring person.
A man in his 50s was arrested at the scene and is being held on suspicion of murder. He is known to be a relative of the victim but his identity has not yet been released. It is not clear whether he was a passenger in the car or was waiting outside.
Eyewitnesses say that after the incident a man was seen standing on the corner of Trent Road holding a knife. As people began to gather he told them not to come near him. Then someone who knew him approached and tried to calm him down and keep him talking until two other men were able to grab his arms and hold him until the police arrived.
Some witnesses have already come forward but police are keen to talk to anyone who saw what happened.
Detectives are still trying to establish a motive for what happened. A moment of violence which destroyed an elderly couple's dreams of spending their final years together.
You can watch Matthew Hudson's full report below: