A SAILOR told his colleague how he was thinking of the best way to "start a massacre" - a year before murdering an officer on board the submarine HMS Astute.

An inquest heard today how Ryan Donovan told fellow seaman Andrew Love that he wanted to stage a "kill frenzy" - a reference to the computer game Grand Theft Auto.

A year later the 23-year-old shot dead Lieutenant Commander Ian Molyneux before shooting another man, Lieutentant Commander Christopher Hodge, in the stomach.

Mr Love's recollection of the chilling conversation was read out at an inquest into the death of Lt Cdr Molyneux during a crazed attack on April 8, 2011.

The inquest has already been told how Donovan had knocked back 20 pints of beer and cider as well as shots of vodka in the 48 hours before his gun rampage.

Navy bosses have said they were not aware of the cocktail of drinks in his system before he was handed a loaded weapon for sentry duty on the day of the tragedy. They have since rolled out new procedures on alcohol use.

Today, one of the officers on board the vessel at the time of the tragedy called for breathalysers to be brought in and for a zero tolerance stance on drinking before duty.

The Royal Navy has tightened its rules on alcohol since the incident took place.

Rules in force at the time of the shooting prevented sailors from drinking ten hours prior to going on duty.

But the Navy has now revised that procedure, upping the alcohol exclusion period to 24 hours.

Donovan is currently serving a minimum of 25 years behind bars for the murder of father-of-four Lt Cdr Molyneux and the attempted murder of Lieutenant Commander Christopher Hodge.

Proceeding