Morris tribunal: A garda sergeant said the only explanation of a superintendent apparently practising a signature was to use it as part of a ruse to get another man to confess.
Sgt Brendan Roache told the inquiry that he had seen Garda Tina Fowley speaking to Insp John McGinley during the detention of several people as part of the inquiry into the death of hit- and-run victim Richie Barron in 1996.
Afterwards, he said Garda Fowley told him the inspector had showed her an apparent signature of Frank McBrearty jnr and asked her, 'Is it a good likeness?' Sgt Roache said at the time he thought the incident was a practical joke by Insp McGinley, but Garda Fowley approached him some years later when the Carty team arrived in Co Donegal to investigate allegations of Garda corruption.
"She was wondering was there more to it than a joke," Sgt Roache said.
"Spell it out," said Michael Durack SC, representing retired superintendent McGinley, who says the incident is an "invention".
"What were the possibilities of what it was?" said Sgt Roache. "Was it a joke, was it a genuine attempt to forge a signature on a confession, or was it an attempt to put to some other prisoner, a ruse to some other prisoner, to get them to make a statement or to admit what they thought was the truth at the time?
"I'm not coming to any theory, Mr Chairman. There was three possibilities. It was a joke, it was a ruse, or it was an attempt to forge a man's signature. The forgery has been ruled out by experts. The joke has been ruled out by Insp McGinley's denial of the incident in the incident room. And now we're left with the other one."
Earlier a British expert gave evidence on effective police interrogation techniques. Det Chief Insp Gary Shaw is attached to the Northumbria police, but is on secondment to Centrex, the Central Police Training and Development Authority.
He said that in the last 20 years the introduction of new guidelines had led to a reduction in the problems of oppressive interviewing in the UK. One of the results of taping interviews was that it was no longer routine for confessions to be challenged in court. Taping was often critical, because written notes would not get across the full story of an interview, while the recording of interviews also "helped the police in stopping unfounded allegations".
He said videotapes were not given to suspects who had been arrested and questioned, and were not distributed to solicitors until charges were brought.
Det Chief Insp Shaw said that a system of supervisors who oversaw interviews and ensured best practice was also essential, and warned of the danger of interrogators developing "tunnel vision" and missing crucial evidence that proves innocence.