Detective Chief Inspector Tim Redfearn is appealing for witnesses following the death of a pensioner, who was killed in a row over a disabled parking space.
The men were waiting in the disabled parking area at the time and got into a disagreement about parking.
We know they became involved in a disagreement which resulted in one man punching the other knocking him to the ground.
It would seem an argument over nothing has led to tragic and devastating consequences for both men and their families.
Anyone with information about the incident, which took place in the Asda supermarket car park in Biggleswade, Bedfordshire, on Saturday, is asked to contact Bedfordshire Police on 101 or Crimestoppers, anonymously, on 0800 555 111.
More top news
MI5 face mounting pressure over claims the IS executioner 'Jihadi John', named yesterday as a London graduate, was known to them
Labour leader Ed Miliband is due to set out his party's plans on how it would cut tuition fees.
New drug driving laws are to come into effect next week, including laws on some prescribed medications.