LETTERS sent by senior gardai to shooting enthusiasts turning down their gun-licence applications shared the same spelling and factual mistakes.
An analysis of refusal letters by 23 garda chief superintendents responsible for issuing firearm licences has concluded that 17 displayed evidence that they were not "independently produced".
Garda guidelines for restricted firearm certificates state that "each case ought to be judged on its own merits, being mindful of the need to apply the legislation in a fair and equitable manner to all applicants".
This, said a linguistics expert asked to analyse refusal letters penned by 23 chief superintendents, implied that each refusal letter should, in principle, be unique in terms of form and content.
But as the authorities move to quell a massive legal action involving up to 200 failed firearms applicants, it has emerged that refusal letters issued by many chief superintendents shared the same grammatical and factual mistakes.
A series of test cases were adjourned last week after one Dublin chief superintendent admitted altering application forms after the legal action began.
Another chief superintendent, who is in line to become an assistant commissioner, admitted that he had failed to complete mandatory sections on statutory application forms, leading to the refusal of many licence applications.
The gardai have denied claims that there is a fixed policy of refusing firearm licences.
And the Department of Justice has not confirmed if a review of the firearm licensing scheme will take place following last week's revelations.
An analysis provided by forensic linguist Michael Coulthard has found that 12 of the letter writers each used the word "shooters" in their letters instead of the word "shooting" in reference to the National Target Shooting Association.
Other similarities included mistaken repetitions of phrases and the typing mistake of "no" instead of the word "not".
Prof Coulthard was asked to examine firearm refusal letters by 23 different chief superintendents and found that the refusal letters of six chief superintendents appeared to have been based on one template, and 11 other chiefs' letters appeared to be based on a second template.
He found that the degree of similarity points "incontestably" to an underlying template letter on which all of the letters have been based.
"There is absolutely no way in which the amount of shared text could have been composed independently nor any possibility of the shared grammatical and factual mistakes being the result of individual superintendents just happening to make those same errors and no others," he said.
"The odds against are incalculably high," said the linguist, who has worked with the Metropolitan, Northern Ireland, Scottish, South Wales and British Military police.
Last Friday, Mr Justice John Hedigan invited the authorities to consider whether they would stand over the garda firearm-licensing system after hearing evidence that a number of application forms were altered after the legal action began. He found that the evidence in two of the three test cases so far showed that the recording process had not been correctly followed.
The test cases resume next Tuesday.