I've seen a reference somewhere to Joseph W Kennedy, head of the Murder Squad (will try to find it again).*
There is a death for a Joseph William Kennedy in Brighton in 1989. Born 30 November 1905.
* It's in a book called The Murder Squad by Gerald McKnight: " Mr Findlay's successor, Chief Superintendent Albert V. Griffin, was to stay until February 1960. He was succeeded, when he finally left, by Joseph W. Kennedy, who was in turn replaced by John Du Rose"