An article by Paul Foot in "Private Eye" suggested that Jackson led one of the teams that bombed Dublin on 17 May 1974, killing 26 people, including two infants. Royal Ulster Constabulary Special Patrol Group (SPG) officer John Weir (who was also involved in loyalist killings), also maintained this in an affidavit. The information from Weir's affidavit was published in 2003 in the "Barron Report", the findings of an official investigation into the Dublin bombings commissioned by Irish Supreme Court Justice Henry Barron. Journalist Kevin Dowling in the "Irish Independent" alleged that Jackson had headed the gang that perpetrated the Miami Showband killings, which left three members of the cabaret band dead and two wounded. Journalist Joe Tiernan and the Pat Finucane Centre alleged this as well as Jackson's involvement in the Dublin bombings. When questioned about the latter, Jackson denied involvement. Findings noted in a report by the Historical Enquiries Team (HET) (released in December 2011) confirmed that Jackson was linked to the Miami Showband attack through his fingerprints, which had been found on the silencer specifically made for the Luger pistol used in the shootings.