A police informer was "the tail wagging the dog" during the investigation into the death of Raphoe cattle dealer Mr Richie Barron, a detective sergeant told the Morris tribunal, writes Gerard Cunningham.
Det Sgt Sylvie Henry outlined to the inquiry the events leading to the arrest of the informer, Mr William Doherty, in September 1997.
Sgt Henry said that in September 1997 he went to see Mr Noel McBride, who had made statements against the McBrearty family. As they were leaving, Mr McBride said, "I can't take it any more." He said he had tried to commit suicide.
"He seemed maybe relieved he was talking about it," the sergeant said.
"We sat in the car. He talked away about all the things that had happened."
Mr McBride said Mr Doherty had come to him and told him what to say in Garda statements.
Sgt Henry had evidence showing phone calls were made from the home of Mr Doherty to the Peoples family in Raphoe. "It was decided to arrest William Doherty," he said. The sergeant said that he saw Mr Doherty as the "kingpin".
"Doherty would approach him and tell him what to say, and shortly after, Garda John O'Dowd would approach him.
"I felt it was a case of the tail wagging the dog. Doherty had John O'Dowd around his little finger."
The sergeant said the arresting officers didn't want any contact between Garda O'Dowd and Mr Doherty "in case Doherty would influence him or vice versa", so Mr Doherty was brought to Milford Garda station for questioning.
Tribunal barrister Mr Anthony Barr SC said Supt Kevin Lennon had said the arrest was an attempt to make him "responsible for the cock-up" of the Barron investigation.
"Definitely not," said Sgt Henry.
Mr Barr outlined Supt Lennon's case that "Milford was a set up by the members of the old investigation team" to draw Supt Lennon into a relationship with Mr Doherty.
"No, that's not the way I see it at all," said Det Sgt Henry. "Doherty was the kingpin. He had O'Dowd round his little finger."