[2] McMahon planted a bomb in Shadow V, a 27-foot (8-metre) fishing boat owned by Mountbatten at Mullaghmore, County Sligo, near Donegal Bay.
McMahon was arrested by the Gardaí at a Garda checkpoint between Longford and Granard on suspicion of driving a stolen vehicle two hours before the bomb detonated.
[3] The IRA claimed responsibility for the bombing in a statement released immediately afterwards that said: "This operation is one of the discriminate ways we can bring to the attention of the English people the continuing occupation of our country.
Garda senior forensic scientist Dr. James O'Donovan examined the clothes McMahon had been wearing at the time of his arrest and was able to uncover flecks of paint from Mountbatten's boat and traces of nitroglycerine.
In an interview for The Telegraph in 2009, Maxwell stated that he had "made two approaches to McMahon, the first through a priest, who warned me in advance that he thought there wouldn't be any positive response.