BOSTON (AP) -- A judge declared a mistrial Wednesday in the corruption case against former Massachusetts Treasurer Tim Cahill after jurors failed to reach a verdict on whether Cahill schemed to run $1.5 million in taxpayer-funded lottery ads to help his unsuccessful 2010 gubernatorial campaign.
Jurors deliberated more than 40 hours over seven days before telling Judge Christine Roach they were hopelessly deadlocked.
The case was the first real test of a 2009 state ethics law. Before the new law was passed, an allegation of conflict of interest would have been a civil rather than a criminal violation.
The new law was sparked by a string of political scandals, including the indictment and subsequent conviction of former Democratic House Speaker Salvatore DiMasi on federal corruption charges.
State Attorney General Martha Coakley, who brought the case against Cahill under the new law, said her office hasn't yet decided whether to re-try Cahill on the charges.
Coakley said her office decided to prosecute Cahill after finding "significant evidence" that he tried to use the lottery's money as his own, to help his campaign.
"Faced with this evidence, we certainly could not ignore it. We did not," she said.
Responding to criticism that the prosecution may have been politically motivated, Coakley said, "It was neither frivolous nor arbitrary for us to bring this case and to ask a jury to decide it."
"No one understands better than I that we do not win them all, but I believe that our office has done the right thing by bringing this case," she said.
"I continue to believe in the strength of this case and the strength of our justice system."
Cahill's former campaign manager, Scott Campbell, was acquitted by the same jury Tuesday.
Cahill testified that he approved the advertising blitz because he wanted to defend the lottery after the Republican Governors Association tarnished its image through a series of negative ads attacking Cahill and his management of the lottery.
After the mistrial was declared, Cahill hugged his wife and smiled, then walked down the front row of the courtroom and hugged each of the friends and family members sitting there. He said he sees the mistrial as a victory.
"I feel it was total vindication," he said.
Asked if he worries Coakley could seek to try him again, Cahill replied, "She can do whatever she wants to do. ... I have no fears."
Cahill, who oversaw the lottery as treasurer, was charged with conspiracy to use his official position to gain an unwarranted privilege and conspiracy to commit procurement fraud. He faced a maximum of five years in prison.
During the monthlong trial, prosecutors portrayed him as a conniving politician who approved an ad blitz touting the benefits of the lottery to run during the month before the election because he hoped it would boost his independent campaign for governor, which by that point was faltering badly. Cahill was also running separate campaign ads touting his leadership of the lottery.
The ads highlighted the success of the lottery in providing millions in funding for local communities. The ads did not show Cahill's image or mention him by name.
Cahill's lawyers, Jeff Denner and Brad Bailey, said that they believe the violations Cahill was accused of should have been civil, not criminal, and that the charges should have been decided by a state ethics commission rather than a jury.
Cahill, who served eight years as state treasurer, then finished a distant third in the governor's race, was asked whether he had any desire to return to public life.
"I don't plan to, no," he said.