Residents of Prince Edward Island have been closely watching the Mike Duffy affair since the senate hired an external auditing firm to look into his expense claims in February 2013.

On Thursday, more than three years after the saga began, P.E.I. Senator Mike Duffy was acquitted of 31 charges.

Judge Charles Vaillancourt sided with the P.E.I. senator, ruling Duffy was not guilty on charges of fraud, bribery and breach of trust.

“There's a big difference between internal rules for claiming expenses and procedures within any kind of organization and the criminal code and with the bar that has to be reached in order to find a criminal conviction,” says Don Desserud, a political science professor at the University of Prince Edward Island.

The charge of most interest to Islanders was the question of Duffy’s residency.

The Crown alleged Duffy had declared his cottage in Cavendish, P.E.I. as his primary residence, despite living primarily at a home in an Ottawa suburb.

“I would like to know more about it in terms of how the judge could determine that he was a resident of P.E.I. and it seems to be pretty clear that, as you're following the case, that he was not spending time here and his main residence was in Ottawa, so that's a surprise,” says Charlottetown resident Susan Hartley.

The judge’s rulings have some P.E.I. residents saying it’s another blow to the already tarnished reputation of the senate.

“I don't think that anybody who pays attention is going to be surprised and there's an awful lot of taxpayers' dollars wasted on the upper chamber,” says Charlottetown resident Mary Phelan.

Don Desserud envisions an even more determined push to abolish the senate.

“I think the public is reaching the point of losing their patience with attempts to reform it, that don't go anywhere. Having said that I've been around this business long enough to know these things wax and wane so people get upset then they forget about it then it's off the radar for a little while,” says Desserud.

Now that Duffy has been found not guilty on all 31 charges, he is entitled to retake his seat in the senate, possibly as early as next Tuesday.

With files from CTV Atlantic’s Jonathan MacInnis.