A New York based lawyer, hired by Annie McCarrick's late father John in 1993 to help find out what happened to his daughter, has expressed his hope that the case will one day be solved.
Gardaí are questioning a 62-year-old businessman for a second day about the murder of Ms McCarrick who went missing in Dublin over 32 years ago.
The businessman, whose home in Co Meath has also been searched, knew Annie McCarrick in the 1990s and is described by gardaí as an associate who moved in her circle.
Originally from New York, Annie McCarrick studied in Ireland in the late 1980s. She moved to Ireland permanently in January 1993 and lived at St Cathryn's Court in Sandymount in Dublin.
She worked as a waitress at the Courtyard Restaurant in Donnybrook and Café Java on Leeson Street.
On 26 March 1993, Ms McCarrick bought groceries in Quinnsworth on Sandymount Road - confirmed by a receipt found in unpacked shopping bags in her apartment. This is the last confirmed activity of Ms McCarrick.
She was reported missing by a friend two days later on 28 March 1993.
Speaking on RTÉ's Morning Ireland, US lawyer Michael Griffith said that the theory that Annie had gone to Enniskerry in Co Wicklow on the day she disappeared turned out to be a "bum steer".
"There was a rumour that Annie was going to Johnny Fox's pub that night because she liked Irish music.
"But the problem with that was, that Annie was working for a bakery next door and she had all these ingredients to make foodstuffs for the next day, and when she left her apartment, all the foodstuffs was there and her personal belongings were not in the dryer, but the wash cycle, giving us a reason to believe that she might be coming back quickly.
"Now the lady who said that she saw Annie get on a bus in Sandymount around 5:30 or so, if she would have gotten to Enniskerry, she would have had to walk like another mile to go to Johnny Fox's because there's no bus service.
"But the problem with that was that music didn't start in Johnny Fox's till about 9 o'clock that night, so it didn't seem plausible that anyone would go up and sit there for two or three hours without the music.
"One of the security people said that he thought he saw Annie come in. But after that, after re-interviewing - that was debunked. So, the Johnny Fox's theory of going up to Wicklow was disposed of," explained Mr Griffith.
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He said: "I'm a very optimistic lawyer. I hope that one day it will have been solved and over the years I've gone to Ireland, I've got some friends there ... and I've made it my business to be interviewed by the garda, by the local press to try to keep the embers burning and I'm delighted to know that there's been an arrest, although there is no conviction at this point, there's only an arrest.
"So let's see what the next developments will be."
Mr Griffith said that he has thought about the case quite a bit over the years and that the loss of Annie had a huge impact on her parents John and Nancy and they later divorced.
"Obviously it was quite a bit of stress that came out of this, and the McCarricks got divorced. And John later became quite upset over the whole situation - Annie, the divorce.
"And I'm trying to do the best that I can to maybe carry on in his stead to help try to give whatever information I can to resolve this matter, hopefully in a conviction," he added.
