Grimson was born in 1959 and was a petty officer in the Royal Navy, serving as a regulator, the navy's own disciplinary and police branch, at Portsmouth.
He killed Nicholas Wright, eighteen, a young sailor, in 1997, and Sion Jenkins, twenty, in 1998, beating them with a baseball bat at his home in Hampshire. He had befriended both.
He was also investigated over the death of Simon Parkes, eighteen, a sailor who disappeared in Gibraltar in 1986 while Grimson was serving there. That case was never brought to trial.
He was convicted of the two Hampshire murders in 2001 and sentenced to life imprisonment. In 2008 the High Court reduced his minimum term on review.
Two convictions stand and the Gibraltar death is an attribution, and the entry is written on that basis. The case had a particular resonance in the Royal Navy because of what he was: the man whose job was to police the conduct of others.